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1.  Characterizing the Epidemiological Transition in Mexico: National and Subnational Burden of Diseases, Injuries, and Risk Factors 
PLoS Medicine  2008;5(6):e125.
Background
Rates of diseases and injuries and the effects of their risk factors can have substantial subnational heterogeneity, especially in middle-income countries like Mexico. Subnational analysis of the burden of diseases, injuries, and risk factors can improve characterization of the epidemiological transition and identify policy priorities.
Methods and Findings
We estimated deaths and loss of healthy life years (measured in disability-adjusted life years [DALYs]) in 2004 from a comprehensive list of diseases and injuries, and 16 major risk factors, by sex and age for Mexico and its states. Data sources included the vital statistics, national censuses, health examination surveys, and published epidemiological studies. Mortality statistics were adjusted for underreporting, misreporting of age at death, and for misclassification and incomparability of cause-of-death assignment. Nationally, noncommunicable diseases caused 75% of total deaths and 68% of total DALYs, with another 14% of deaths and 18% of DALYs caused by undernutrition and communicable, maternal, and perinatal diseases. The leading causes of death were ischemic heart disease, diabetes mellitus, cerebrovascular disease, liver cirrhosis, and road traffic injuries. High body mass index, high blood glucose, and alcohol use were the leading risk factors for disease burden, causing 5.1%, 5.0%, and 7.3% of total burden of disease, respectively. Mexico City had the lowest mortality rates (4.2 per 1,000) and the Southern region the highest (5.0 per 1,000); under-five mortality in the Southern region was nearly twice that of Mexico City. In the Southern region undernutrition and communicable, maternal, and perinatal diseases caused 23% of DALYs; in Chiapas, they caused 29% of DALYs. At the same time, the absolute rates of noncommunicable disease and injury burdens were highest in the Southern region (105 DALYs per 1,000 population versus 97 nationally for noncommunicable diseases; 22 versus 19 for injuries).
Conclusions
Mexico is at an advanced stage in the epidemiologic transition, with the majority of the disease and injury burden from noncommunicable diseases. A unique characteristic of the epidemiological transition in Mexico is that overweight and obesity, high blood glucose, and alcohol use are responsible for larger burden of disease than other noncommunicable disease risks such as tobacco smoking. The Southern region is least advanced in the epidemiological transition and suffers from the largest burden of ill health in all disease and injury groups.
Gretchen Stevens and colleagues estimate deaths and loss of healthy life years (measured in disability-adjusted life years, DALYs) for Mexico as a whole and its 32 states.
Editors' Summary
Background.
The impact that a particular disease has upon a population is known as the “burden of disease.” This burden is estimated by considering how many deaths the disease causes and how much it disables those still living. The relative contributions of different diseases and injuries to the loss of healthy life from death and disability vary greatly among countries. Broadly speaking, in low-income countries (such as many African countries), infectious diseases and undernutrition are the major causes of ill health and death whereas in high-income countries (for example, the United States), noncommunicable diseases such as heart disease, diabetes, and stroke are more important. As poor countries become richer, they experience a change in the pattern of disease away from infectious diseases and malnutrition and toward noncommunicable diseases. Health experts call this change the “epidemiological transition” (epidemiology is the study of the distribution and causes of diseases in populations). Governments need to know as much as possible about which diseases have the greatest burden—and about where the country is in the epidemiological transition—to help them implement effective health policies. For example, there is no point in setting up treatment centers for a specific infectious disease in a country where the disease no longer occurs. Equally importantly, governments need to know which lifestyle choices and other genetic and environmental factors affect the chances of people in their country developing specific diseases so that they can provide relevant educational and intervention programs.
Why Was This Study Done?
Most analyses of the burden of disease have been done at the national and global scale. However, in middle-income countries, different regions of the country may be at different stages of the epidemiological transition and may, therefore, have very different patterns of disease. In this study, the researchers investigate whether this is the case for Mexico, a middle-income country that has developed rapidly over the past few decades. Mexico recently reformed its health system to improve access to health care for the poor and underserved. Under this new system, individual states play an important role in allocating health-care resources (as they do in many other countries) so it is very important to know how the burden of disease varies in different states of the country.
What Did the Researchers Do and Find?
The researchers estimated deaths and loss of healthy life years caused by various diseases and injuries for Mexico and its states using data from death registers, censuses, health examination surveys, and epidemiological studies. Loss of healthy life years was measured using a metric called “disability-adjusted life years” (DALYs)—one DALY is equivalent to the loss of one year of healthy life because of premature death or disability. They also identified the major risk factors for these diseases and injuries across the country. Nationally, noncommunicable diseases (particularly heart disease, diabetes, stroke, and liver cirrhosis) caused 75% of deaths and 68% of DALYs. Undernutrition, infectious diseases, and problems occurring in mothers and infants around the time of birth (maternal and perinatal diseases) caused 14% of deaths and 18% of DALYs. The leading risk factors for disease in Mexico were being overweight, having high blood glucose, and alcohol use. When the researchers studied different regions of the country, they found that Mexico City had the lowest death rate whereas the relatively undeveloped Southern region of Mexico had the highest, particularly among young children. In Chiapas, the most southerly state of Mexico, undernutrition and infectious, maternal, and perinatal diseases caused nearly a third of DALYs. In addition to the highest infectious disease burden, the Southern region also had the highest noncommunicable disease and injury burden per head of population.
What Do These Findings Mean?
These findings indicate that Mexico as a nation is at an advanced stage of the epidemiological transition. In other words, because of the improvement in its economic status, the burden of disease caused by infectious diseases and undernutrition has decreased, and noncommunicable diseases now cause the largest share of the total burden of disease. However, the study also shows that the poorest regions of the country, which have the highest overall burden of disease, are lagging behind the richer regions in terms of their position in the epidemiological transition. Thus different health priorities need to be set in different regions of Mexico (and in other middle-income countries where the burden of disease is also likely to vary with region). Finally, the information provided by this study about the forces driving the epidemiological transition in Mexico, such as the importance of obesity and alcohol use, should help public-health officials decide how to improve the overall health of the Mexican population.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0050125.
A related PLoS Medicine Perspective by Martin Tobias further discusses this research
The World Health Organization provides information on the Global Burden of Disease Project including links to other burden of disease resources. It also provides detailed information on various aspects of health in Mexico (in several languages), and an explanation of DALYs
Read a detailed article on the “epidemiological transition” by Abdel Omran, who proposed this idea in 1971
A large amount of Mexican data is available online for Spanish speakers. Complete raw mortality statistics can be found on the Mexican Ministry of Health's Web site http://sinais.salud.gob.mx/sinais.php. Also online is the complete report of the ENSANUT survey (Encuesta Nacional de Salud y Nutrición 2006) http://www.insp.mx/ensanut/, which was one of the major data sources used to determine risk factor exposure
doi:10.1371/journal.pmed.0050125
PMCID: PMC2429945  PMID: 18563960
2.  Estimating Population Cause-Specific Mortality Fractions from in-Hospital Mortality: Validation of a New Method 
PLoS Medicine  2007;4(11):e326.
Background
Cause-of-death data for many developing countries are not available. Information on deaths in hospital by cause is available in many low- and middle-income countries but is not a representative sample of deaths in the population. We propose a method to estimate population cause-specific mortality fractions (CSMFs) using data already collected in many middle-income and some low-income developing nations, yet rarely used: in-hospital death records.
Methods and Findings
For a given cause of death, a community's hospital deaths are equal to total community deaths multiplied by the proportion of deaths occurring in hospital. If we can estimate the proportion dying in hospital, we can estimate the proportion dying in the population using deaths in hospital. We propose to estimate the proportion of deaths for an age, sex, and cause group that die in hospital from the subset of the population where vital registration systems function or from another population. We evaluated our method using nearly complete vital registration (VR) data from Mexico 1998–2005, which records whether a death occurred in a hospital. In this validation test, we used 45 disease categories. We validated our method in two ways: nationally and between communities. First, we investigated how the method's accuracy changes as we decrease the amount of Mexican VR used to estimate the proportion of each age, sex, and cause group dying in hospital. Decreasing VR data used for this first step from 100% to 9% produces only a 12% maximum relative error between estimated and true CSMFs. Even if Mexico collected full VR information only in its capital city with 9% of its population, our estimation method would produce an average relative error in CSMFs across the 45 causes of just over 10%. Second, we used VR data for the capital zone (Distrito Federal and Estado de Mexico) and estimated CSMFs for the three lowest-development states. Our estimation method gave an average relative error of 20%, 23%, and 31% for Guerrero, Chiapas, and Oaxaca, respectively.
Conclusions
Where accurate International Classification of Diseases (ICD)-coded cause-of-death data are available for deaths in hospital and for VR covering a subset of the population, we demonstrated that population CSMFs can be estimated with low average error. In addition, we showed in the case of Mexico that this method can substantially reduce error from biased hospital data, even when applied to areas with widely different levels of development. For countries with ICD-coded deaths in hospital, this method potentially allows the use of existing data to inform health policy.
Working in Mexico and using vital registration data, Chris Murray and colleagues achieved encouraging results with a new method to estimate population cause-specific mortality fractions.
Editors' Summary
Background.
Governments and international health agencies need accurate information on the leading causes of death in different populations to help them develop and monitor effective health policies and programs. It is pointless investing money in screening programs for a type of cancer in a country where that cancer is very rare, for example, or setting up treatment centers for an infectious disease in a region where the disease no longer occurs. In developed countries, most deaths are recorded in vital registration (VR) systems. These databases record the specific cause of death, which is assigned by doctors using the International Classification of Diseases (ICD), an internationally agreed-upon list of codes for hundreds of diseases. Across the developing world, however, only one death in four is recorded by VR systems; in some very poor countries, only one death in 20 is recorded accurately. With this paucity of cause-of-death data, developing countries cannot make good decisions about how to spend their limited resources.
Why Was This Study Done?
The establishment of full VR systems in all developing countries will take time and may not always be possible, but many of these nations already collect ICD-coded data on in-hospital deaths. Unfortunately, this information does not accurately reflect the causes of death across whole populations. For example, the diseases that affect rich people differ from those that affect poor people, and rich people are more likely to die in hospital than poor people. Thus, although for each cause of death, the number of deaths in hospital equals the total number of deaths in the community multiplied by the proportion of deaths occurring in hospital, this proportion is different for each cause. If these proportions could be estimated, then in-hospital death records could be used to determine the fraction of the population that dies from each cause—the population's “cause-specific mortality fractions” (CSMFs). In this study, the researchers have devised a method that allows them to do this, and have used near-complete VR data collected between 1998 and 2005 in Mexico to test their method.
What Did the Researchers Do and Find?
The researchers developed a mathematical method that estimates the proportion of deaths occurring in hospitals for people grouped together by their age, sex, and cause of death (an “age–sex–cause group”) using VR data from a subset of the whole population. They tested their method for 45 nonoverlapping but all-encompassing diseases using the Mexican VR data (which records when a person has died in the hospital). They found that if they decreased the amount of VR data used to estimate the proportion of each age, sex, cause group dying in hospital from 100% to 9%, the maximum relative error between the true and estimated CSMFs was only 12%. When they just used the VR information from the capital city (9% of the population), the average relative error in CSMFs (a measure of how much the estimated and true CSMFs differ) across all 45 causes of death was only 10%. Finally, when they used VR data for the main urban area of Mexico (where access to hospitals is good) to estimate CSMFs for the three least developed states of Mexico, the average relative errors were 20%, 23%, and 31%.
What Do These Findings Mean?
These findings indicate that the researchers' method can provide accurate estimates of population CSMFs using ICD-coded cause-of-death data from deaths in hospital and VR data that cover part of the population. Even when the VR data from a developed area are used to calculate the CSMFs in a poorly developed area, the method produces a more accurate estimate than in-hospital death data used alone. Because the researchers have only tested their method for one country, additional “validation studies” need to be done using data from other countries with a good-quality VR system. If the method does work in these other settings, then existing data on in-hospital deaths could be used to determine the leading causes of death in countries with poor VR systems. Such information would be invaluable in establishing effective health policies.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0040326.
• An accompanying paper by the same authors describes an alternative approach to collecting accurate cause-of-death data in developing countries
• The World Health Organization provides information on health statistics and health information systems, on the International Classification of Diseases, and on the Health Metrics Network, a global collaboration focused on improving sources of vital statistics and cause-of-death data
• Grand Challenges in Global Health provides information on research into better ways for developing countries to measure their health status
doi:10.1371/journal.pmed.0040326
PMCID: PMC2080647  PMID: 18031195
3.  Characterizing the Epidemiology of the 2009 Influenza A/H1N1 Pandemic in Mexico 
PLoS Medicine  2011;8(5):e1000436.
Gerardo Chowell and colleagues address whether school closures and other social distancing strategies were successful in reducing pandemic flu transmission in Mexico by analyzing the age- and state-specific incidence of influenza morbidity and mortality in 32 Mexican states.
Background
Mexico's local and national authorities initiated an intense public health response during the early stages of the 2009 A/H1N1 pandemic. In this study we analyzed the epidemiological patterns of the pandemic during April–December 2009 in Mexico and evaluated the impact of nonmedical interventions, school cycles, and demographic factors on influenza transmission.
Methods and Findings
We used influenza surveillance data compiled by the Mexican Institute for Social Security, representing 40% of the population, to study patterns in influenza-like illness (ILIs) hospitalizations, deaths, and case-fatality rate by pandemic wave and geographical region. We also estimated the reproduction number (R) on the basis of the growth rate of daily cases, and used a transmission model to evaluate the effectiveness of mitigation strategies initiated during the spring pandemic wave. A total of 117,626 ILI cases were identified during April–December 2009, of which 30.6% were tested for influenza, and 23.3% were positive for the influenza A/H1N1 pandemic virus. A three-wave pandemic profile was identified, with an initial wave in April–May (Mexico City area), a second wave in June–July (southeastern states), and a geographically widespread third wave in August–December. The median age of laboratory confirmed ILI cases was ∼18 years overall and increased to ∼31 years during autumn (p<0.0001). The case-fatality ratio among ILI cases was 1.2% overall, and highest (5.5%) among people over 60 years. The regional R estimates were 1.8–2.1, 1.6–1.9, and 1.2–1.3 for the spring, summer, and fall waves, respectively. We estimate that the 18-day period of mandatory school closures and other social distancing measures implemented in the greater Mexico City area was associated with a 29%–37% reduction in influenza transmission in spring 2009. In addition, an increase in R was observed in late May and early June in the southeast states, after mandatory school suspension resumed and before summer vacation started. State-specific fall pandemic waves began 2–5 weeks after school reopened for the fall term, coinciding with an age shift in influenza cases.
Conclusions
We documented three spatially heterogeneous waves of the 2009 A/H1N1 pandemic virus in Mexico, which were characterized by a relatively young age distribution of cases. Our study highlights the importance of school cycles on the transmission dynamics of this pandemic influenza strain and suggests that school closure and other mitigation measures could be useful to mitigate future influenza pandemics.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
From June 2009 to August 2010, the world was officially (according to specific World Health Organization [WHO] criteria—WHO phase 6 pandemic alert) in the grip of an Influenza A pandemic with a new strain of the H1N1 virus. The epidemic in Mexico, which had the second confirmed global case of H1N1 virus was first noted in early April 2009, when reports of respiratory hospitalizations and deaths among 62 young adults in Mexico alerted local health officials to the occurrence of atypical rates of respiratory illness. In line with its inter-institutional National Pandemic Influenza Preparedness and Response Plan, the Ministry of Health cancelled school attendance in the greater Mexico City area on April 24 and expanded these measures to the rest the country three days later. The Ministry of Health then implemented in Mexico City other “social distancing” strategies such as closing cinemas and restaurants and cancelling large public gatherings.
Why Was This Study Done?
School closures and other intense social distancing strategies can be very disruptive to the population, but as yet it is uncertain whether these measures were successful in reducing disease transmission. In addition, there have been no studies concentrating on recurrent pandemic waves in Mexico. So in this study the authors addressed these issues by analyzing the age- and state-specific incidence of influenza morbidity and mortality in 32 Mexican States and quantified the association between local influenza transmission rates, school cycles, and demographic factors.
What Did the Researchers Do and Find?
The researchers used the epidemiological surveillance system of the Mexican Institute for Social Security—a Mexican health system that covers private sector workers and their families, a group representative of the general population, that comprises roughly 40% of the Mexican population (107 million individuals), with a network of 1,099 primary health care units and 259 hospitals nationwide. Then the researchers compiled state- and age-specific time series of incident influenza-like illness and H1N1 influenza cases by day of symptom onset to analyze the geographic dissemination patterns of the pandemic across Mexico and defined three temporally distinct pandemic waves in 2009: spring (April 1–May 20), summer (May 21–August 1), and fall (August 2–December 31). The researchers then applied a mathematical model of influenza transmission to daily case data to assess the effectiveness of mandatory school closures and other social distancing measures implemented during April 24–May 11, in reducing influenza transmission rates.
The Mexican Institute for Social Security reported a total of 117,626 people with influenza-like illness from April 1 to December 31, 2009, of which 36,044 were laboratory tested (30.6%) and 27,440 (23.3%) were confirmed with H1N1 influenza. During this period, 1,370 people with influenza-like illness died of which 585 (1.5 per 100,000) were confirmed to have H1N1 influenza. The median age of people with laboratory confirmed influenza like illness (H1N1) was 18 years overall but increased to 31 years during the autumn wave. The overall case-fatality ratio among people with influenza like illness was 1.2%, but highest (5.5%) among people over 60 years. The researchers found that the 18-day period of mandatory school closures and other social distancing measures implemented in the greater Mexico City area was associated with a substantial (29%–37%) reduction in influenza transmission in spring 2009 but increased in late May and early June in the southeast states, after mandatory school suspension resumed and before summer vacation started. State-specific pandemic waves began 2–5 weeks after school reopened for the fall term, coinciding with an age shift in influenza cases.
What Do These Findings Mean?
These findings show that the age distribution of pandemic influenza morbidity was greater in younger age groups, while the risk of severe disease was skewed towards older age groups, and that there were substantial geographical variation in pandemic patterns across Mexico, in part related to population size. But most importantly, these findings support the effectiveness of early mitigation efforts including mandatory school closures and cancellation of large public gatherings, reinforcing the importance of school cycles in the transmission of pandemic influenza. This analysis increases understanding of the age and transmission patterns of the Mexican 2009 influenza pandemic at various geographic scales, which is crucial for designing more efficient public health interventions against future influenza pandemics.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000436.
The World Health Organization provides information about the global response to the 2009 H1N1 pandemic
doi:10.1371/journal.pmed.1000436
PMCID: PMC3101203  PMID: 21629683
4.  Clinical Benefits, Costs, and Cost-Effectiveness of Neonatal Intensive Care in Mexico 
PLoS Medicine  2010;7(12):e1000379.
Joshua Salomon and colleagues performed a cost-effectiveness analysis using health and economic outcomes following preterm birth in Mexico and showed that neonatal intensive care provided high value for the money in this setting.
Background
Neonatal intensive care improves survival, but is associated with high costs and disability amongst survivors. Recent health reform in Mexico launched a new subsidized insurance program, necessitating informed choices on the different interventions that might be covered by the program, including neonatal intensive care. The purpose of this study was to estimate the clinical outcomes, costs, and cost-effectiveness of neonatal intensive care in Mexico.
Methods and Findings
A cost-effectiveness analysis was conducted using a decision analytic model of health and economic outcomes following preterm birth. Model parameters governing health outcomes were estimated from Mexican vital registration and hospital discharge databases, supplemented with meta-analyses and systematic reviews from the published literature. Costs were estimated on the basis of data provided by the Ministry of Health in Mexico and World Health Organization price lists, supplemented with published studies from other countries as needed. The model estimated changes in clinical outcomes, life expectancy, disability-free life expectancy, lifetime costs, disability-adjusted life years (DALYs), and incremental cost-effectiveness ratios (ICERs) for neonatal intensive care compared to no intensive care. Uncertainty around the results was characterized using one-way sensitivity analyses and a multivariate probabilistic sensitivity analysis. In the base-case analysis, neonatal intensive care for infants born at 24–26, 27–29, and 30–33 weeks gestational age prolonged life expectancy by 28, 43, and 34 years and averted 9, 15, and 12 DALYs, at incremental costs per infant of US$11,400, US$9,500, and US$3,000, respectively, compared to an alternative of no intensive care. The ICERs of neonatal intensive care at 24–26, 27–29, and 30–33 weeks were US$1,200, US$650, and US$240, per DALY averted, respectively. The findings were robust to variation in parameter values over wide ranges in sensitivity analyses.
Conclusions
Incremental cost-effectiveness ratios for neonatal intensive care imply very high value for money on the basis of conventional benchmarks for cost-effectiveness analysis.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Most pregnancies last about 40 weeks but increasing numbers of babies are being born preterm, before they reach 37 weeks of gestation (the period during which a baby develops in its mother). In developed countries and some middle-income countries such as Mexico, improvements in the care of newborn babies (neonatal intensive care) mean that more preterm babies survive now than in the past. Nevertheless, preterm birth is still a major cause of infant death worldwide that challenges attainment of Target 5 of Millennium Development Goal 4—the reduction of the global under-five mortality rate by two-thirds of the 1990 rate by 2015 (the Millennium Development Goals, which were agreed by world leaders in 2000, aim to reduce world poverty). Furthermore, many preterm babies who survive have long-term health problems and disabilities such as cerebral palsy, deafness, or learning difficulties. The severity of these disabilities and their long-term costs to families and to society depend on the baby's degree of prematurity.
Why Was This Study Done?
Mexico recently reformed its health system in an effort to improve access to care, particularly for the poorest sections of its population, and to improve the quality of its health care. The central component of this health care reform is the System of Social Protection of Health (SSPH). The SSPH contains a family health insurance program—Seguro Popular—that aims to provide the 50 million uninsured people living in Mexico with free access to an explicit set of health care interventions. As with any insurance program, decisions have to be made about which interventions Seguro Poplar should cover. Should neonatal intensive care be covered, for example? Do the benefits of this intervention (increased survival of babies) outweigh the costs of neonatal care and of long-term care for survivors with disabilities? In other words, is neonatal intensive care cost-effective? In this study, the researchers investigate this question by estimating the clinical benefits, costs, and cost-effectiveness of neonatal intensive care in Mexico.
What Did the Researchers Do and Find?
The researchers built a decision analytic model, a mathematical model that combines evidence on the outcomes and costs of alternative treatments to help inform decisions about health care policy. They gathered data about the health outcomes of preterm births in Mexico from registers of births and deaths and from hospital discharge databases, and estimated the costs of neonatal intensive care and long-term care for disabled survivors using data from the Mexican Ministry of Health and the World Health Organization. They then applied their model, which estimates changes in parameters such as life expectancy, lifetime costs, disability-adjusted life years (DALYs; one DALY represents the loss of a year of healthy life), and incremental cost-effectiveness ratios (ICERs; the additional cost expended for each DALY averted) for neonatal intensive care compared to no intensive care, to a group of 2 million infants. Neonatal intensive care for infants born at 24–26, 27–29, and 30–33 weeks gestation prolonged life expectancy by 28, 43, and 34 years and averted 9, 15, and 12 DALYs at incremental costs of US$11,000, US$10,000, and US$3000, respectively, compared to no intensive care. The ICERs of neonatal intensive care for babies born at these times were US$1200, US$700, and US$300 per DALY averted, respectively.
What Do These Findings Mean?
Interventions with ICERs of less than a country's per capita gross domestic product (GDP) are highly cost-effective; those with ICERs of 1–3 times the per capita GDP are potentially cost-effective. Mexico's per capita GDP in 2005 was approximately US$8,200. Thus, neonatal intensive care could provide exceptional value for money in Mexico (and maybe in other middle-income countries), even for very premature babies. The accuracy of these findings inevitably depends on the assumptions used to build the decision analytic model and on the accuracy of the data fed into it, but the findings were little changed by a wide range of alterations that the researchers made to the model. Importantly, however, this cost-effectiveness analysis focuses on health and economic consequences of different intervention choices, and does not capture all aspects of well-being. Decisions regarding neonatal intensive care will need to be based on a full consideration of all relevant factors, including ethical issues, and cost-effectiveness analyses should continue to be updated as new data emerge on health outcomes and costs associated with neonatal intensive care.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000379.
The March of Dimes, a nonprofit organization for pregnancy and baby health, provides information on preterm birth (in English and Spanish)
The Nemours Foundation, another nonprofit organization for child health, also provides information on premature babies (in English and Spanish)
MedlinePlus provides links to other information on premature babies (in English and Spanish)
The United Nations Childrens Fund (UNICEF) works for children's rights, survival, development and protection around the world; it provides information on Millennium Development Goal 4 and its Childinfo website provides detailed statistics about child survival and health (some information in several languages)
A PLoS Medicine Policy Forum by Núria Homedes and Antonio Ugalde discusses health care reforms in Mexico
doi:10.1371/journal.pmed.1000379
PMCID: PMC3001895  PMID: 21179496
5.  The Influence of Distance and Level of Care on Delivery Place in Rural Zambia: A Study of Linked National Data in a Geographic Information System 
PLoS Medicine  2011;8(1):e1000394.
Using linked national data in a geographic information system system, Sabine Gabrysch and colleagues investigate the effects of distance to care and level of care on women's use of health facilities for delivery in rural Zambia.
Background
Maternal and perinatal mortality could be reduced if all women delivered in settings where skilled attendants could provide emergency obstetric care (EmOC) if complications arise. Research on determinants of skilled attendance at delivery has focussed on household and individual factors, neglecting the influence of the health service environment, in part due to a lack of suitable data. The aim of this study was to quantify the effects of distance to care and level of care on women's use of health facilities for delivery in rural Zambia, and to compare their population impact to that of other important determinants.
Methods and Findings
Using a geographic information system (GIS), we linked national household data from the Zambian Demographic and Health Survey 2007 with national facility data from the Zambian Health Facility Census 2005 and calculated straight-line distances. Health facilities were classified by whether they provided comprehensive EmOC (CEmOC), basic EmOC (BEmOC), or limited or substandard services. Multivariable multilevel logistic regression analyses were performed to investigate the influence of distance to care and level of care on place of delivery (facility or home) for 3,682 rural births, controlling for a wide range of confounders. Only a third of rural Zambian births occurred at a health facility, and half of all births were to mothers living more than 25 km from a facility of BEmOC standard or better. As distance to the closest health facility doubled, the odds of facility delivery decreased by 29% (95% CI, 14%–40%). Independently, each step increase in level of care led to 26% higher odds of facility delivery (95% CI, 7%–48%). The population impact of poor geographic access to EmOC was at least of similar magnitude as that of low maternal education, household poverty, or lack of female autonomy.
Conclusions
Lack of geographic access to emergency obstetric care is a key factor explaining why most rural deliveries in Zambia still occur at home without skilled care. Addressing geographic and quality barriers is crucial to increase service use and to lower maternal and perinatal mortality. Linking datasets using GIS has great potential for future research and can help overcome the neglect of health system factors in research and policy.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Approximately 360,000 women die each year in pregnancy and childbirth, of which more than 200,000 in sub-Saharan Africa, where a woman's lifetime risk of dying during or following pregnancy remains as high as 1 in 31 (compared to 1 in 4,300 in the developed world). The target of Millennium Development Goal 5 is to reduce the maternal mortality ratio by three quarters by 2015. Most maternal and neonatal deaths in low-income countries could be prevented if all women delivered their babies in settings where skilled birth attendants (such as midwives) were available and could provide emergency obstetric care to both mothers and babies in case of complications. Yet every year roughly 50 million women give birth at home without skilled care.
Why was this study done?
The likelihood of a woman giving birth in a health facility under the care of a skilled birth attendant depends on many factors. These include characteristics of the mother and her family, such as education level and household wealth, and aspects of the health service environment—distance to the nearest health facility and the quality of care provided at that facility, for example. However, research to date has typically focused on household and individual factors, neglecting the influence of the health service environment on choice of delivery place, largely because suitable data was not available. In this study in rural Zambia, the researchers aimed to quantify the effects of the health service environment, namely distance to health care and the level of care provided, on pregnant women's use of health facilities for giving birth. To put these factors in context, the researchers compared the impact of distance to quality care on place of delivery to that of other important factors, such as poverty and education.
What did the researchers do and find?
Using a geographic information system (GIS), the researchers linked national household data (from the 2007 Zambia Demographic and Health Survey) with national facility data (from the 2005 Zambian Health Facility Census) and calculated straight-line distances between women's villages and health facilities. Health facilities were classified as providing comprehensive emergency obstetric care, basic emergency obstetric care, or limited or substandard services by using reported capability to perform a certain number of the eight emergency obstetric care signal functions: injectable antibiotics, injectable oxytocics, injectable anticonvulsants, manual removal of placenta, manual removal of retained products, assisted vaginal delivery, cesarean section, and blood transfusion, as well as criteria on staffing, opening hours and referral capacity. The researchers used data from 3,682 rural births and multivariable multilevel logistic regression analyses to investigate whether distance to, and level of care at the closest delivery facility influence place of delivery (health facility or home), keeping other influential factors constant.
The researchers found that only a third of births in rural Zambia occurred at a health facility, and half of all mothers who gave birth lived more than 25 km from a health facility that provided basic emergency obstetric services. As distance to the closest health facility doubled, the odds of a women giving birth in a health facility decreased by 29%. Independently, each step increase in the level of emergency obstetric care provided at the closest delivery facility led to an increased likelihood (26% higher odds) of a woman delivering her baby at a facility. The researchers estimated that the impact of poor geographic access to emergency obstetric services was of similar magnitude as that of low maternal education, household poverty, or lack of female autonomy.
What do these findings mean?
The results of this study suggest that poor geographic access to emergency obstetric care is a key factor in explaining why most women in rural Zambia still deliver their babies at home without skilled care. Therefore, in order to increase the number of women delivering in health facilities and thus reduce maternal and neonatal mortality, it is crucial to address the geographic and quality barriers to delivery service use. Furthermore, the methodology used in this study—linking datasets using GIS— has great potential for future research as it can help explore the influence of health system factors also for other health problems.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000394.
Information about emergency obstetric care is provided by the United Nations Population Fund (UNFPA)
Various topics on maternal health are presented by WHO, WHO Regional Office Africa, by UNPFA, and UNICEF
WHO offers detailed information about MDG5
Family Care International offers more information about maternal and neonatal health
The Averting Maternal Death and Disability program (AMDD) provides information on needs assessments of emergency obstetric and newborn care
Countdown to 2015 tracks progress in maternal, newborn, and child survival
WHO provides free online viewing of BBC Fight for Life videos describing delivery experiences in different countries
doi:10.1371/journal.pmed.1000394
PMCID: PMC3026699  PMID: 21283606
6.  Socioeconomic factors and the risk of anencephaly in a Mexican population: a case-control study. 
Public Health Reports  2005;120(1):39-45.
OBJECTIVE: The study was designed to evaluate the association between socioeconomic level (as measured by maternal education, maternal occupation, and monthly family income) and anencephaly. METHODS: The authors conducted a case-control study using data from the Epidemiological Surveillance System Register for Neural Tube Defects for three states of the Mexican Republic: Puebla, Guerrero and the State of Mexico. Mothers of 151 cases of infants born with anencephaly and mothers of 151 control infants born during the period March 2000 to February 2001 were interviewed about their socioeconomic characteristics and other factors including reproductive history, use of prenatal care, use of tobacco and alcohol, fever during pregnancy, and folic acid supplementation. RESULTS: After adjustment for potential confounders, a risk gradient was seen with decreasing maternal education. Women with less than a primary school education (adjusted odds ratio [OR]=3.0; 95% confidence interval [CI] 1.2, 7.6) and women who had completed primary school but had not completed junior high school (adjusted OR=2.2; 95% CI 0.9, 5.7) had higher risks of giving birth to an infant with anencephaly, compared to women with a higher educational level. A monthly income < or = 1,000 pesos (approximately dollars 100 U.S.) was also associated with a higher risk of anencephaly (OR=2.5; 95% CI 1.2, 5.1). Women employed in industry or agriculture during the acute risk period (three months prior to conception to one month after conception) had a risk 6.5 times (95% CI 1.4, 29.6) that of professional and business women. CONCLUSIONS: This study helps to identify groups that may be especially vulnerable to this type of congenital malformation so that primary and secondary preventive strategies can be targeted to these groups.
PMCID: PMC1497685  PMID: 15736330
7.  Air Cleaning Technologies 
Executive Summary
Objective
This health technology policy assessment will answer the following questions:
When should in-room air cleaners be used?
How effective are in-room air cleaners?
Are in-room air cleaners that use combined HEPA and UVGI air cleaning technology more effective than those that use HEPA filtration alone?
What is the Plasmacluster ion air purifier in the pandemic influenza preparation plan?
The experience of severe acute respiratory syndrome (SARS) locally, nationally, and internationally underscored the importance of administrative, environmental, and personal protective infection control measures in health care facilities. In the aftermath of the SARS crisis, there was a need for a clearer understanding of Ontario’s capacity to manage suspected or confirmed cases of airborne infectious diseases. In so doing, the Walker Commission thought that more attention should be paid to the potential use of new technologies such as in-room air cleaning units. It recommended that the Medical Advisory Secretariat of the Ontario Ministry of Health and Long-Term Care evaluate the appropriate use and effectiveness of such new technologies.
Accordingly, the Ontario Health Technology Advisory Committee asked the Medical Advisory Secretariat to review the literature on the effectiveness and utility of in-room air cleaners that use high-efficiency particle air (HEPA) filters and ultraviolet germicidal irradiation (UVGI) air cleaning technology.
Additionally, the Ontario Health Technology Advisory Committee prioritized a request from the ministry’s Emergency Management Unit to investigate the possible role of the Plasmacluster ion air purifier manufactured by Sharp Electronics Corporation, in the pandemic influenza preparation plan.
Clinical Need
Airborne transmission of infectious diseases depends in part on the concentration of breathable infectious pathogens (germs) in room air. Infection control is achieved by a combination of administrative, engineering, and personal protection methods. Engineering methods that are usually carried out by the building’s heating, ventilation, and air conditioning (HVAC) system function to prevent the spread of airborne infectious pathogens by diluting (dilution ventilation) and removing (exhaust ventilation) contaminated air from a room, controlling the direction of airflow and the air flow patterns in a building. However, general wear and tear over time may compromise the HVAC system’s effectiveness to maintain adequate indoor air quality. Likewise, economic issues may curtail the completion of necessary renovations to increase its effectiveness. Therefore, when exposure to airborne infectious pathogens is a risk, the use of an in-room air cleaner to reduce the concentration of airborne pathogens and prevent the spread of airborne infectious diseases has been proposed as an alternative to renovating a HVAC system.
Airborne transmission is the spread of infectious pathogens over large distances through the air. Infectious pathogens, which may include fungi, bacteria, and viruses, vary in size and can be dispersed into the air in drops of moisture after coughing or sneezing. Small drops of moisture carrying infectious pathogens are called droplet nuclei. Droplet nuclei are about 1 to 5μm in diameter. This small size in part allows them to remain suspended in the air for several hours and be carried by air currents over considerable distances. Large drops of moisture carrying infectious pathogens are called droplets. Droplets being larger than droplet nuclei, travel shorter distances (about 1 metre) before rapidly falling out of the air to the ground. Because droplet nuclei remain airborne for longer periods than do droplets, they are more amenable to engineering infection control methods than are droplets.
Droplet nuclei are responsible for the airborne transmission of infectious diseases such as tuberculosis, chicken pox (varicella), measles (rubeola), and dessiminated herpes zoster, whereas close contact is required for the direct transmission of infectious diseases transmitted by droplets, such as influenza (the flu) and SARS.
The Technology
In-room air cleaners are supplied as portable or fixed devices. Fixed devices can be attached to either a wall or ceiling and are preferred over portable units because they have a greater degree of reliability (if installed properly) for achieving adequate room air mixing and airflow patterns, which are important for optimal effectiveness.
Through a method of air recirculation, an in-room air cleaner can be used to increase room ventilation rates and if used to exhaust air out of the room it can create a negative-pressure room for airborne infection isolation (AII) when the building’s HVAC system cannot do so. A negative-pressure room is one where clean air flows into the room but contaminated air does not flow out of it. Contaminated room air is pulled into the in-room air cleaner and cleaned by passing through a series of filters, which remove the airborne infectious pathogens. The cleaned air is either recirculated into the room or exhausted outside the building. By filtering contaminated room air and then recirculating the cleaned air into the room, an in-room air cleaner can improve the room’s ventilation. By exhausting the filtered air to the outside the unit can create a negative-pressure room. There are many types of in-room air cleaners. They vary widely in the airflow rates through the unit, the type of air cleaning technology used, and the technical design.
Crucial to maximizing the efficiency of any in-room air cleaner is its strategic placement and set-up within a room, which should be done in consultation with ventilation engineers, infection control experts, and/or industrial hygienists. A poorly positioned air cleaner may disrupt airflow patterns within the room and through the air cleaner, thereby compromising its air cleaning efficiency.
The effectiveness of an in-room air cleaner to remove airborne pathogens from room air depends on several factors, including the airflow rate through the unit’s filter and the airflow patterns in the room. Tested under a variety of conditions, in-room air cleaners, including portable or ceiling mounted units with either a HEPA or a non-HEPA filter, portable units with UVGI lights only, or ceiling mounted units with combined HEPA filtration and UVGI lights, have been estimated to be between 30% and 90%, 99% and 12% and 80% effective, respectively. However, and although their effectiveness is variable, the United States Centers for Disease Control and Prevention has acknowledged in-room air cleaners as alternative technology for increasing room ventilation when this cannot be achieved by the building’s HVAC system with preference given to fixed recirculating systems over portable ones.
Importantly, the use of an in-room air cleaner does not preclude either the need for health care workers and visitors to use personal protective equipment (N95 mask or equivalent) when entering AII rooms or health care facilities from meeting current regulatory requirements for airflow rates (ventilation rates) in buildings and airflow differentials for effective negative-pressure rooms.
The Plasmacluster ion technology, developed in 2000, is an air purification technology. Its manufacturer, Sharp Electronics Corporation, says that it can disable airborne microorganisms through the generation of both positive and negative ions. (1) The functional unit is the hydroxyl, which is a molecule comprised of one oxygen molecule and one hydrogen atom.
Plasmacluster ion air purifier uses a multilayer filter system composed of a prefilter, a carbon filter, an antibacterial filter, and a HEPA filter, combined with an ion generator to purify the air. The ion generator uses an alternating plasma discharge to split water molecules into positively and negatively charged ions. When these ions are emitted into the air, they are surrounded by water molecules and form cluster ions which are attracted to airborne particles. The cluster ion surrounds the airborne particle, and the positive and negative ions react to form hydroxyls. These hydroxyls steal the airborne particle’s hydrogen atom, which creates a hole in the particle’s outer protein membrane, thereby rendering it inactive.
Because influenza is primarily acquired by large droplets and direct and indirect contact with an infectious person, any in-room air cleaner will have little benefit in controlling and preventing its spread. Therefore, there is no role for the Plasmacluster ion air purifier or any other in-room air cleaner in the control of the spread of influenza. Accordingly, for purposes of this review, the Medical Advisory Secretariat presents no further analysis of the Plasmacluster.
Review Strategy
The objective of the systematic review was to determine the effectiveness of in-room air cleaners with built in UVGI lights and HEPA filtration compared with those using HEPA filtration only.
The Medical Advisory Secretariat searched the databases of MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, INAHATA (International Network of Agencies for Health Technology Assessment), Biosis Previews, Bacteriology Abstracts, Web of Science, Dissertation Abstracts, and NIOSHTIC 2.
A meta-analysis was conducted if adequate data was available from 2 or more studies and where statistical and clinical heterogeneity among studies was not an issue. Otherwise, a qualitative review was completed. The GRADE system was used to summarize the quality of the body of evidence comprised of 1 or more studies.
Summary of Findings
There were no existing health technology assessments on air cleaning technology located during the literature review. The literature search yielded 59 citations of which none were retained. One study was retrieved from a reference list of a guidance document from the United States Centers for Disease Control and Prevention, which evaluated an in-room air cleaner with combined UVGI lights and HEPA filtration under 2 conditions: UVGI lights on and UVGI lights off. Experiments were performed using different ventilation rates and using an aerosolized pathogen comprised of Mycobaterium parafortuitum, a surrogate for the bacterium that causes tuberculosis. Effectiveness was measured as equivalent air changes per hour (eACH). This single study formed the body of evidence for our systematic review research question.
Experimental Results
The eACH rate for the HEPA-UVGI in-room air cleaner was statistically significantly greater when the UV lights were on compared with when the UV lights were off. (P < .05). However, subsequent experiments could not attribute this to the UVGI. Consequently, the results are inconclusive and an estimate of effect (benefit) is uncertain.
The study was reviewed by a scientific expert and rated moderate for quality. Further analysis determined that there was some uncertainty in the directness of the outcome measure (eACH); thus, the GRADE level for the quality of the evidence was low indicating that an estimate of effect is very uncertain.
There is uncertainty in the benefits of using in-room air cleaners with combined UVGI lights and HEPA filtration over systems that use HEPA filtration alone. However, there are no known risks to using systems with combined UVGI and HEPA technology compared with those with HEPA alone. There is an increase in the burden of cost including capital costs (cost of the device), operating costs (electricity usage), and maintenance costs (cleaning and replacement of UVGI lights) to using an in-room air cleaner with combined UVGI and HEPA technology compared with those with HEPA alone. Given the uncertainty of the estimate of benefits, an in-room air cleaner with HEPA technology only may be an equally reasonable alternative to using one with combined UVGI and HEPA technology
Conclusions
In-room air cleaners may be used to protect health care staff from air borne infectious pathogens such as tuberculosis, chicken pox, measles, and dessiminated herpes zoster. In addition, and although in-room air cleaners are not effective at protecting staff and preventing the spread of droplet-transmitted diseases such as influenza and SARS, they may be deployed in situations with a novel/emerging infectious agent whose epidemiology is not yet defined and where airborne transmission is suspected.
It is preferable that in-room air cleaners be used with a fixed and permanent room placement when ventilation requirements must be improved and the HVAC system cannot be used. However, for acute (temporary) situations where a novel/emerging infectious agent presents whose epidemiology is not yet defined and where airborne transmission is suspected it may be prudent to use the in room air cleaner as a portable device until mode of transmission is confirmed. To maximize effectiveness, consultation with an environmental engineer and infection control expert should be undertaken before using an in-room air cleaner and protocols for maintenance and monitoring of these devices should be in place.
If properly installed and maintained, in room air cleaners with HEPA or combined HEPA and UVGI air cleaning technology are effective in removing airborne pathogens. However, there is only weak evidence available at this time regarding the benefit of using an in-room air cleaner with combined HEPA and UVGI air cleaner technology instead of those with HEPA filter technology only.
PMCID: PMC3382390  PMID: 23074468
8.  A Binational Overview of Reproductive Health Outcomes Among US Hispanic and Mexican Women in the Border Region 
Introduction
The US–Mexico border region has 15 million residents and 300,000 births annually. Reproductive health concerns have been identified on both sides of the border, but comparable information about reproductive health is not available. The objective of this study was to compare reproductive health indicators among populations in this region.
Methods
We used 2009 US Hispanic and Mexican birth certificate data to compare births inside the border region, elsewhere within the border states, and in the United States and Mexico overall. We examined trends in total fertility and birth rates using birth data from 2000 through 2009 and intercensal population estimates.
Results
Among women in the border region, US women had more lifetime births than Mexican women in 2009 (2.69 births vs 2.15 births) and throughout the decade. Birth rates in the group aged 15 to 19 years were high in both the US (73.8/1,000) and Mexican (86.7/1,000) border regions. Late or no prenatal care was nearly twice as prevalent in the border regions as in the nonborder regions of border states. Low birth weight and preterm and early-term birth were more prevalent in the US border than in the Mexican border region; US border rates were higher and Mexican rates were lower than their corresponding nonborder and national rates. We found some variations within border states.
Conclusion
These findings constitute the first population-based information on the reproductive health of the entire Hispanic US–Mexico border population. Evidence of disparities warrants exploration at state and local levels. Teen pregnancy and inadequate prenatal care are shared problems in US–Mexico border communities and suggest an area for binational cooperation.
doi:10.5888/pcd10.130019
PMCID: PMC3748278  PMID: 23948338
9.  Screening Mammography for Women Aged 40 to 49 Years at Average Risk for Breast Cancer 
Executive Summary
Objective
The aim of this review was to determine the effectiveness of screening mammography in women aged 40 to 49 years at average risk for breast cancer.
Clinical Need
The effectiveness of screening mammography in women aged over 50 years has been established, yet the issue of screening in women aged 40 to 49 years is still unsettled. The Canadian Task Force of Preventive Services, which sets guidelines for screening mammography for all provinces, supports neither the inclusion nor the exclusion of this screening procedure for 40- to 49-year-old women from the periodic health examination. In addition to this, 2 separate reviews, one conducted in Quebec in 2005 and the other in Alberta in 2000, each concluded that there is an absence of convincing evidence on the effectiveness of screening mammography for women in this age group who are at average risk for breast cancer.
In the United States, there is disagreement among organizations on whether population-based mammography should begin at the age of 40 or 50 years. The National Institutes of Health, the American Association for Cancer Research, and the American Academy of Family Physicians recommend against screening women in their 40s, whereas the United States Preventive Services Task Force, the National Cancer Institute, the American Cancer Society, the American College of Radiology, and the American College of Obstetricians and Gynecologists recommend screening mammograms for women aged 40 to 49 years. Furthermore, in comparing screening guidelines between Canada and the United States, it is also important to recognize that “standard care” within a socialized medical system such as Canada’s differs from that of the United States. The National Breast Screening Study (NBSS-1), a randomized screening trial conducted in multiple centres across Canada, has shown there is no benefit in mortality from breast cancer from annual mammograms in women randomized between the ages of 40 and 49, relative to standard care (i.e. physical exam and teaching of breast-self examination on entry to the study, with usual community care thereafter).
At present, organized screening programs in Canada systematically screen women starting at 50 years of age, although with a physician’s referral, a screening mammogram is an insured service in Ontario for women under 50 years of age.
International estimates of the epidemiology of breast cancer show that the incidence of breast cancer is increasing for all ages combined, whereas mortality is decreasing, though at a slower rate. These decreasing mortality rates may be attributed to screening and advances in breast cancer therapy over time. Decreases in mortality attributable to screening may be a result of the earlier detection and treatment of invasive cancers, in addition to the increased detection of ductal carcinoma in situ (DCIS), of which certain subpathologies are less lethal. Evidence from the SEER cancer registry in the United States indicates that the age-adjusted incidence of DCIS has increased almost 10-fold over a 20-year period (from 2.7 to 25 per 100,000).
The incidence of breast cancer is lower in women aged 40 to 49 years than in women aged 50 to 69 years (about 140 per 100,000 versus 500 per 100,000 women, respectively), as is the sensitivity (about 75% versus 85% for women aged under and over 50, respectively) and specificity of mammography (about 80% versus 90% for women aged under and over 50, respectively). The increased density of breast tissue in younger women is mainly responsible for the lower accuracy of this procedure in this age group. In addition, as the proportion of breast cancers that occur before the age of 50 are more likely to be associated with genetic predisposition as compared with those diagnosed in women after the age of 50, mammography may not be an optimal screening method for younger women.
Treatment options vary with the stage of disease (based on tumor size, involvement of surrounding tissue, and number of affected axillary lymph nodes) and its pathology, and may include a combination of surgery, chemotherapy, and/or radiotherapy.
Surgery is the first-line intervention for biopsy confirmed tumours. The subsequent use of radiation, chemotherapy, or hormonal treatments is dependent on the histopathologic characteristics of the tumor and the type of surgery. There is controversy regarding the optimal treatment of DCIS, which is noninvasive.
With such controversy as to the effectiveness of mammography and the potential risk associated with women being overtreated or actual cancers being missed, and the increased risk of breast cancer associated with exposure to annual mammograms over a 10-year period, the Ontario Health Technology Advisory Committee requested this review of screening mammography in women aged 40 to 49 years at average risk for breast cancer. This review is the first of 2 parts and concentrates on the effectiveness of screening mammography (i.e., film mammography, FM) for women at average risk aged 40 to 49 years. The second part will be an evaluation of screening by either magnetic resonance imaging or digital mammography, with the objective of determining the optimal screening modality in these younger women.
Review Strategy
The following questions were asked:
Does screening mammography for women aged 40 to 49 years who are at average risk for breast cancer reduce breast cancer mortality?
What is the sensitivity and specificity of mammography for this age group?
What are the risks associated with annual screening from ages 40 to 49?
What are the risks associated with false positive and false negative mammography results?
What are the economic considerations if evidence for effectiveness is established?
The Medical Advisory Secretariat followed its standard procedures and searched these electronic databases: Ovid MEDLINE, EMBASE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews and the International Network of Agencies for Health Technology Assessment.
Keywords used in the search were breast cancer, breast neoplasms, mass screening, and mammography.
In total, the search yielded 6,359 articles specific to breast cancer screening and mammography. This did not include reports on diagnostic mammograms. The search was further restricted to English-language randomized controlled trials (RCTs), systematic reviews, and meta-analyses published between 1995 and 2005. Excluded were case reports, comments, editorials, and letters, which narrowed the results to 516 articles and previous health technology policy assessments.
These were examined against the criteria outlined below. This resulted in the inclusion of 5 health technology assessments, the Canadian Preventive Services Task Force report, the United States Preventive Services Task Force report, 1 Cochrane review, and 8 RCTs.
Inclusion Criteria
English-language articles, and English and French-language health technology policy assessments, conducted by other organizations, from 1995 to 2005
Articles specific to RCTs of screening mammography of women at average risk for breast cancer that included results for women randomized to studies between the ages of 40 and 49 years
Studies in which women were randomized to screening with or without mammography, although women may have had clinical breast examinations and/or may have been conducting breast self-examination.
UK Age Trial results published in December 2006.
Exclusion Criteria
Observational studies, including those nested within RCTs
RCTs that do not include results on women between the ages of 40 and 49 at randomization
Studies in which mammography was compared with other radiologic screening modalities, for example, digital mammography, magnetic resonance imaging or ultrasound.
Studies in which women randomized had a personal history of breast cancer.
Intervention
Film mammography
Comparators
Within RCTs, the comparison group would have been women randomized to not undergo screening mammography, although they may have had clinical breast examinations and/or have been conducting breast self-examination.
Outcomes of Interest
Breast cancer mortality
Summary of Findings
There is Level 1 Canadian evidence that screening women between the ages of 40 and 49 years who are at average risk for breast cancer is not effective, and that the absence of a benefit is sustained over a maximum follow-up period of 16 years.
All remaining studies that reported on women aged under 50 years were based on subset analyses. They provide additional evidence that, when all these RCTs are taken into account, there is no significant reduction in breast cancer mortality associated with screening mammography in women aged 40 to 49 years.
Conclusions
There is Level 1 evidence that screening mammography in women aged 40 to 49 years at average risk for breast cancer is not effective in reducing mortality.
Moreover, risks associated with exposure to mammographic radiation, the increased risk of missed cancers due to lower mammographic sensitivity, and the psychological impact of false positives, are not inconsequential.
The UK Age Trial results published in December 2006 did not change these conclusions.
PMCID: PMC3377515  PMID: 23074501
10.  The Prevalence of Hypertension in Older Mexicans and Mexican Americans 
Ethnicity & disease  2008;18(3):294-298.
Objective
To evaluate the prevalence of hypertension in older Mexicans in the United States and Mexico.
Design
Stratified by sex, logistic regression models to predict physician diagnosed hypertension were conducted using the Hispanic EPESE (wave 3) and the Mexican Health and Aging Study (MHAS- 70 years and older) datasets.
Setting
Five Southwestern States of Texas, Arizona, California, Colorado, and New Mexico in the United States.
Participants
Older Mexican and Mexican Americans ages 70 and over living in the United States and Mexico.
Main Outcome Measures
Physician diagnosed hypertension.
Results
Older Mexican and Mexican American women have a greater prevalence of hypertension than their male counterparts. Mexican women, who have migrated to the United States and returned to Mexico, have similarly high rates of hypertension as their female counterparts in the United States. After adjusting for demographic characteristics, obesity, and smoking, older Mexican and Mexican American women who have migrated or immigrated to the United States are at increased risk for hypertension.
Conclusions
Gender differences exist in hypertension risk for older Mexicans and Mexican Americans living in the United States and Mexico. Older women who migrate to the United States are at a particular risk for hypertension in both the United States and Mexico.
PMCID: PMC3086015  PMID: 18785442
Emigration and Immigration; Hypertension; Mexican Americans; Aged
11.  Micro-regional planning: evidence-based community buy-in for health development in five of Mexico’s poorest rural districts 
BMC Health Services Research  2011;11(Suppl 2):S2.
Background
Community participation was a core tenet of Primary Health Care as articulated in the 1970s. How this could be generated and maintained was less clear. This historical article describes development of protocols for evidence-based community mobilisation in five local administrative units (municipios) in the Mexican state of Guerrero between 1992 and 1995.
Methods
A sample of five to eight sentinel sites represented each of the most impoverished municipalities of the poorest five of the state's seven regions. A 1992 baseline survey of diarrhoea and its actionable determinants provided the substrate for discussion with local planners and communities. Municipal planners used different strategies to promote participation. In one municipality, new health committees took control of water quality. In another, municipal authorities hired health promoters; a song promoted oral rehydration, and house-to-house interpersonal discussions promoted chlorination. In the poorest and most mountainous municipality, radio casera (home-made radio) soap operas used local "stars". In the largest and most disparate municipality, a child-to-family scheme relied on primary and secondary school teachers. The research team assessed outcomes at intervals and used the results to reinforce local planning and action.
Results
Diarrhoea rates declined in all five municipalities, and there were several positive intermediate outcomes from the communication strategies – changing knowledge, household practices and uptake of services. There was a strong link between specific contents of the communication package and the changing knowledge or practices.
Conclusions
Apart from these evidence-based interventions, other factors probably contributed to the decline of childhood diarrhoea. But, by monitoring implementation of planning decisions and the impact this has at community level, micro-regional planning can stimulate and reinforce actions likely to improve the health of communities. The process empowered municipalities to get access to more resources from the state government and international agencies.
doi:10.1186/1472-6963-11-S2-S2
PMCID: PMC3332561  PMID: 22375532
12.  Evaluation of Internet-Based Dengue Query Data: Google Dengue Trends 
Dengue is a common and growing problem worldwide, with an estimated 70–140 million cases per year. Traditional, healthcare-based, government-implemented dengue surveillance is resource intensive and slow. As global Internet use has increased, novel, Internet-based disease monitoring tools have emerged. Google Dengue Trends (GDT) uses near real-time search query data to create an index of dengue incidence that is a linear proxy for traditional surveillance. Studies have shown that GDT correlates highly with dengue incidence in multiple countries on a large spatial scale. This study addresses the heterogeneity of GDT at smaller spatial scales, assessing its accuracy at the state-level in Mexico and identifying factors that are associated with its accuracy. We used Pearson correlation to estimate the association between GDT and traditional dengue surveillance data for Mexico at the national level and for 17 Mexican states. Nationally, GDT captured approximately 83% of the variability in reported cases over the 9 study years. The correlation between GDT and reported cases varied from state to state, capturing anywhere from 1% of the variability in Baja California to 88% in Chiapas, with higher accuracy in states with higher dengue average annual incidence. A model including annual average maximum temperature, precipitation, and their interaction accounted for 81% of the variability in GDT accuracy between states. This climate model was the best indicator of GDT accuracy, suggesting that GDT works best in areas with intense transmission, particularly where local climate is well suited for transmission. Internet accessibility (average ∼36%) did not appear to affect GDT accuracy. While GDT seems to be a less robust indicator of local transmission in areas of low incidence and unfavorable climate, it may indicate cases among travelers in those areas. Identifying the strengths and limitations of novel surveillance is critical for these types of data to be used to make public health decisions and forecasting models.
Author Summary
Dengue is a common and growing problem worldwide. Delays in traditional surveillance systems limit the ability of public health agencies to identify and respond to dengue outbreaks efficiently. Internet search queries provide near real-time indicators of infectious disease activity and have proven effective for monitoring disease activity in some countries, but have not been assessed on smaller geographic areas. We compared Google Dengue Trends data for 17 states in Mexico to traditional surveillance data from those states. We found that the utility of Google Dengue Trends at the state-level is highly variable and depends on climatic conditions supporting dengue virus transmission. Novel surveillance tools like Google Dengue Trends can provide timely information to public health agencies, but to be useful on a local scale, they must be considered within the local context of dengue transmissibility.
doi:10.1371/journal.pntd.0002713
PMCID: PMC3937307  PMID: 24587465
13.  Measuring Under-Five Mortality: Validation of New Low-Cost Methods 
PLoS Medicine  2010;7(4):e1000253.
n/a
Background
There has been increasing interest in measuring under-five mortality as a health indicator and as a critical measure of human development. In countries with complete vital registration systems that capture all births and deaths, under-five mortality can be directly calculated. In the absence of a complete vital registration system, however, child mortality must be estimated using surveys that ask women to report the births and deaths of their children. Two survey methods exist for capturing this information: summary birth histories and complete birth histories. A summary birth history requires a minimum of only two questions: how many live births has each mother had and how many of them have survived. Indirect methods are then applied using the information from these two questions and the age of the mother to estimate under-five mortality going back in time prior to the survey. Estimates generated from complete birth histories are viewed as the most accurate when surveys are required to estimate under-five mortality, especially for the most recent time periods. However, it is much more costly and labor intensive to collect these detailed data, especially for the purpose of generating small area estimates. As a result, there is a demand for improvement of the methods employing summary birth history data to produce more accurate as well as subnational estimates of child mortality.
Methods and Findings
We used data from 166 Demographic and Health Surveys (DHS) to develop new empirically based methods of estimating under-five mortality using children ever born and children dead data. We then validated them using both in- and out-of-sample analyses. We developed a range of methods on the basis of three dimensions of the problem: (1) approximating the average length of exposure to mortality from a mother's set of children using either maternal age or time since first birth; (2) using cohort and period measures of the fraction of children ever born that are dead; and (3) capturing country and regional variation in the age pattern of fertility and mortality. We focused on improving estimates in the most recent time periods prior to a survey where the traditional indirect methods fail. In addition, all of our methods incorporated uncertainty. Validated against under-five estimates generated from complete birth histories, our methods outperformed the standard indirect method by an average of 43.7% (95% confidence interval [CI] 41.2–45.2). In the 5 y prior to the survey, the new methods resulted in a 53.3% (95% CI 51.3–55.2) improvement. To illustrate the value of this method for local area estimation, we applied our new methods to an analysis of summary birth histories in the 1990, 2000, and 2005 Mexican censuses, generating subnational estimates of under-five mortality for each of 233 jurisdictions.
Conclusions
The new methods significantly improve the estimation of under-five mortality using summary birth history data. In areas without vital registration data, summary birth histories can provide accurate estimates of child mortality. Because only two questions are required of a female respondent to generate these data, they can easily be included in existing survey programs as well as routine censuses of the population. With the wider application of these methods to census data, countries now have the means to generate estimates for subnational areas and population subgroups, important for measuring and addressing health inequalities and developing local policy to improve child survival.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Every year, more than 8 million children die before their fifth birthdays. Most of these deaths occur in developing countries, and most are the result of diseases or combinations of diseases that could have been prevented or treated. Measles, for example, is a major killer in low-income countries and undernutrition contributes to one-third of childhood deaths. Faced with this largely avoidable loss of young lives, in 1990, the United Nations' World Summit for Children pledged to improve the survival of children. Later, in 2000, world leaders set a target of reducing child mortality to one-third of its 1990 level by 2015 as Millennium Development Goal 4. This goal, together with seven others, is designed to alleviate extreme poverty by 2015. In 2006, for the first time since mortality records began, annual deaths among children under five fell below 10 million as a result of public-health programs such as the Measles Initiative, which has reduced global measles mortality by more than two-thirds by vaccinating 500 million children, and the Nothing but Nets campaign, which distributed insecticide-treated antimalaria nets in Africa.
Why Was This Study Done?
Although global under-five mortality is declining, it is unlikely that Millennium Development Goal 4 will be reached by 2015. Indeed, in some countries, little or no progress is being made toward this goal. To improve progress and to monitor the effects of public-health interventions, accurate, up-to-date estimates of national and subnational child mortality rates are essential. In developed countries, vital registration systems—records of all births and deaths—mean that under-five mortality rates can be directly calculated. But many developing countries lack vital registration systems, and child mortality has to be estimated using data collected in surveys. In “complete birth history” surveys, mothers are asked numerous questions about each living child and each dead child. Such surveys can be used to estimate under-five mortality accurately for recent time periods but they are expensive and time-consuming. By contrast, in “summary birth history” surveys, each mother is simply asked how many live births she had and how many of her children have survived. Under-five mortality can be indirectly calculated from this information and the age of the mother, but the current methods for making this calculation cannot provide reliable estimates of under-five mortality more recently than 3 years before the survey. In this study, therefore, the researchers develop methods for estimating more recent under-five mortality rates from summary birth histories.
What Did the Researchers Do and Find?
The researchers used data about all children born and dead children extracted from 169 Demographic and Health Surveys (DHS; a project started in 1984 to help developing countries collect data on health and population trends) covering 70 countries to develop four new methods to estimate under-five mortality. They tested these new methods and a method that combined all four approaches by comparing the estimates of under-five mortality provided by these methods and the standard indirect method to the estimates obtained from an analysis of the complete birth data in the DHS. The new methods all outperformed the standard indirect method, particularly for the most recent 5 years. The researchers also used their new methods to generate estimates of under-five mortality for each of the 233 jurisdictions in Mexico from summary birth histories collected in the 1990, 2000, and 2005 Mexico censuses. The overall trends of these subnational estimates, they report, mirrored those obtained from vital registration data.
What Do These Findings Mean?
These findings suggest that application of the new methods developed by the researchers could significantly improve the accuracy of estimates of under-five mortality based on summary birth history data. The researchers warn that although their methods can provide accurate estimates of recent under-five mortality, they might not capture rapid fluctuations in mortality such as those that occur during wars. However, they suggest, the two questions needed to generate the data required to apply these new methods could easily be included in existing survey programs and in routine censuses. Consequently, systematic application of the methods proposed in this study should provide policy makers with the information about levels, recent trends, and inequalities in child mortality that they need to accelerate efforts to reduce the global toll of childhood deaths.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000253.
This study and two related PLoS Medicine Research Articles by Obermeyer et al and by Murray et al are further discussed in a PLoS Medicine Perspective by Mathers and Boerma
The United Nations Childrens Fund (UNICEF) works for children's rights, survival, development and protection around the world; it provides information on Millennium Development Goal 4 and its Childinfo website provides detailed statistics about child survival and health (some information in several languages)
Further information about the Millennium Development Goals is available
The World Health Organization also has information about Millennium Development Goal 4 and provides estimates of child mortality rates
Information is also available about the Demographic and Health Surveys
doi:10.1371/journal.pmed.1000253
PMCID: PMC2854123  PMID: 20405055
14.  Relatedness Analyses of Histoplasma capsulatum Isolates from Mexican Patients with AIDS-Associated Histoplasmosis by Using Histoplasmin Electrophoretic Profiles and Randomly Amplified Polymorphic DNA Patterns 
Journal of Clinical Microbiology  1999;37(5):1404-1408.
The present paper analyzes the histoplasmin electrophoretic profiles and the randomly amplified polymorphic DNA (RAPD) patterns of the fungus Histoplasma capsulatum isolated from Mexican patients with AIDS-associated histoplasmosis. Clinical isolates from Guatemala, Colombia, and Panama, as well as H. capsulatum isolates from different sources in nature, were also processed. All histoplasmin samples shared four antigenic fractions of 200, 49, 10.5, and 8.5 kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). According to their percentage of relatedness, based on SDS-PAGE histoplasmin electrophoretic image analysis, H. capsulatum isolates were divided in two groups: group A contained all AIDS-associated isolates studied and two human reference strains from Mexican histoplasmosis patients without AIDS; group B included bat guano, infected bat, and cock excreta isolates from the State of Guerrero, Mexico, plus three human histoplasmosis strains from Guatemala, Panama, and Colombia. Polymorphic DNA patterns evaluated by RAPD-PCR showed three major bands of 4.4, 3.2, and 2.3 kb in most H. capsulatum isolates studied. Four groups were related by DNA polymorphisms: group I was formed by most of the AIDS-associated H. capsulatum isolates studied, one human histoplasmosis strain from Colombia, two human reference strains from Mexican patients without AIDS, and one human histoplasmosis strain from Guatemala. Group II consisted of only a single strain from Panama. Group III included three strains: one from a Mexican patient with AIDS and two isolated from nature in Guerrero (cock excreta and bat guano). The last, group IV, consisted of only one strain isolated from an infected bat, captured in Guerrero. A tight relationship between phenotypic and genotypic characterization was observed, and both analyses could be useful tools for typing H. capsulatum from different sources and geographic origins.
PMCID: PMC84786  PMID: 10203495
15.  Configuring Balanced Scorecards for Measuring Health System Performance: Evidence from 5 Years' Evaluation in Afghanistan 
PLoS Medicine  2011;8(7):e1001066.
Anbrasi Edward and colleagues report the results of a balanced scorecard performance system used to examine 29 key performance indicators over a 5-year period in Afghanistan, between 2004 and 2008.
Background
In 2004, Afghanistan pioneered a balanced scorecard (BSC) performance system to manage the delivery of primary health care services. This study examines the trends of 29 key performance indicators over a 5-year period between 2004 and 2008.
Methods and Findings
Independent evaluations of performance in six domains were conducted annually through 5,500 patient observations and exit interviews and 1,500 provider interviews in >600 facilities selected by stratified random sampling in each province. Generalized estimating equation (GEE) models were used to assess trends in BSC parameters. There was a progressive improvement in the national median scores scaled from 0–100 between 2004 and 2008 in all six domains: patient and community satisfaction of services (65.3–84.5, p<0.0001); provider satisfaction (65.4–79.2, p<0.01); capacity for service provision (47.4–76.4, p<0.0001); quality of services (40.5–67.4, p<0.0001); and overall vision for pro-poor and pro-female health services (52.0–52.6). The financial domain also showed improvement until 2007 (84.4–95.7, p<0.01), after which user fees were eliminated. By 2008, all provinces achieved the upper benchmark of national median set in 2004.
Conclusions
The BSC has been successfully employed to assess and improve health service capacity and service delivery using performance benchmarking during the 5-year period. However, scorecard reconfigurations are needed to integrate effectiveness and efficiency measures and accommodate changes in health systems policy and strategy architecture to ensure its continued relevance and effectiveness as a comprehensive health system performance measure. The process of BSC design and implementation can serve as a valuable prototype for health policy planners managing performance in similar health care contexts.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Traditionally, the performance of a health system (the complete network of health care agencies, facilities, and providers in a defined geographical region) has been measured in terms of health outcomes: how many people have been treated, how many got better, and how many died. But, nowadays, with increased demand for improved governance and accountability, policy makers are seeking comprehensive performance measures that show in detail how innovations designed to strengthen health systems are affecting service delivery and health outcomes. One such performance measure is the “balanced scorecard,” an integrated management and measurement tool that enables organizations to clarify their vision and strategy and translate them into action. The balanced scorecard—essentially a list of key performance indicators and performance benchmarks in several domains—was originally developed for industry but is now becoming a popular strategic management tool in the health sector. For example, balanced scorecards have been successfully integrated into the Dutch and Italian public health care systems.
Why Was This Study Done?
Little is known about the use of balanced scorecards in the national public health care systems of developing countries but the introduction of performance management into health system reform in fragile states in particular (developing countries where the state fails to perform the fundamental functions necessary to meet its citizens' basic needs and expectations) could help to promote governance and leadership, and facilitate essential policy changes. One fragile state that has introduced the balanced scorecard system for public health care management is Afghanistan, which emerged from decades of conflict in 2002 with some of the world's worst health indicators. To deal with an extremely high burden of disease, the Ministry of Public Health (MOPH) designed a Basic Package of Health Services (BPHS), which is delivered by nongovernmental organizations and MOPH agencies. In 2004, the MOPH introduced the National Health Service Performance Assessment (NHSPA), an annual country-wide assessment of service provision and patient satisfaction and pioneered a balanced scorecard, which uses data collected in the NHSPA, to manage the delivery of primary health care services. In this study, the researchers examine the trends between 2004 and 2008 of the 29 key performance indicators in six domains included in this balanced scorecard, and consider the potential and limitations of the scorecard as a management tool to measure and improve health service delivery in Afghanistan and other similar countries.
What Did the Researchers Do and Find?
Each year of the study, a random sample of 25 facilities (district hospitals and comprehensive and basic health centers) in 28 of Afghanistan's 34 provinces was chosen (one province did not have functional facilities in 2004 and the other five missing provinces were inaccessible because of ongoing conflicts). NHSPA surveyors collected approximately 5,000 patient observations, 5,000 exit interviews with patients or their caregivers, and 1,500 health provider interviews by observing consultations involving five children under 5 years old and five patients over 5 years old in each facility. The researchers then used this information to evaluate the key performance indicators in the balanced scorecard and a statistical method called generalized estimating equation modeling to assess trends in these indicators. They report that there was a progressive improvement in national average scores in all six domains (patients and community satisfaction with services, provider satisfaction, capacity for service provision, quality of services, overall vision for pro-poor and pro-female health services, and financial systems) between 2004 and 2008.
What Do These Findings Mean?
These findings suggest that the balanced scorecard was successfully used to improve health system capacity and service delivery through performance benchmarking over the 5-year study period. Importantly, the use of the balanced scorecard helped to show the effects of investments, facilitate policy change, and create a more evidence-based decision-making culture in Afghanistan's primary health care system. However, the researchers warn that the continuing success of the balanced scorecard in Afghanistan will depend on its ability to accommodate changes in health systems policy. Furthermore, reconfigurations of the scorecard are needed to include measures of the overall effectiveness and efficiency of the health system such as mortality rates. More generally, the researchers conclude that the balanced scorecard offers a promising measure of health system performance that could be used to examine the effectiveness of health care strategies and innovations in other fragile and developing countries.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001066.
A 2010 article entitled An Afghan Success Story: The Balanced Scorecard and Improved Health Services in The Globe, a newsletter produced by the Department of International Health at the John Hopkins Bloomberg School of Public Health, provides a detailed description of the balanced scorecard used in this study
Wikipedia has a page on health systems and on balanced scorecards (note that Wikipedia is a free online encyclopedia that anyone can edit; available in several languages)
The World Health Organization country profile of Afghanistan provides information on the country's health system and burden of disease (in several languages)
doi:10.1371/journal.pmed.1001066
PMCID: PMC3144209  PMID: 21814499
16.  Cost-Effectiveness of Breast Cancer Control Strategies in Central America: The Cases of Costa Rica and Mexico 
PLoS ONE  2014;9(4):e95836.
This paper reports the most cost-effective policy options to support and improve breast cancer control in Costa Rica and Mexico. Total costs and effects of breast cancer interventions were estimated using the health care perspective and WHO-CHOICE methodology. Effects were measured in disability-adjusted life years (DALYs) averted. Costs were assessed in 2009 United States Dollars (US$). To the extent available, analyses were based on locally obtained data. In Costa Rica, the current strategy of treating breast cancer in stages I to IV at a 80% coverage level seems to be the most cost-effective with an incremental cost-effectiveness ratio (ICER) of US$4,739 per DALY averted. At a coverage level of 95%, biennial clinical breast examination (CBE) screening could improve Costa Rica's population health twofold, and can still be considered very cost-effective (ICER US$5,964/DALY). For Mexico, our results indicate that at 95% coverage a mass-media awareness raising program (MAR) could be the most cost-effective (ICER US$5,021/DALY). If more resources are available in Mexico, biennial mammography screening for women 50–70 yrs (ICER US$12,718/DALY), adding trastuzumab (ICER US$13,994/DALY) or screening women 40–70 yrs biennially plus trastuzumab (ICER US$17,115/DALY) are less cost-effective options. We recommend both Costa Rica and Mexico to engage in MAR, CBE or mammography screening programs, depending on their budget. The results of this study should be interpreted with caution however, as the evidence on the intervention effectiveness is uncertain. Also, these programs require several organizational, budgetary and human resources, and the accessibility of breast cancer diagnostic, referral, treatment and palliative care facilities should be improved simultaneously. A gradual implementation of early detection programs should give the respective Ministries of Health the time to negotiate the required budget, train the required human resources and understand possible socioeconomic barriers.
doi:10.1371/journal.pone.0095836
PMCID: PMC4000228  PMID: 24769920
17.  Multi-purpose HealthCare Telemedicine Systems with mobile communication link support 
The provision of effective emergency telemedicine and home monitoring solutions are the major fields of interest discussed in this study. Ambulances, Rural Health Centers (RHC) or other remote health location such as Ships navigating in wide seas are common examples of possible emergency sites, while critical care telemetry and telemedicine home follow-ups are important issues of telemonitoring. In order to support the above different growing application fields we created a combined real-time and store and forward facility that consists of a base unit and a telemedicine (mobile) unit. This integrated system: can be used when handling emergency cases in ambulances, RHC or ships by using a mobile telemedicine unit at the emergency site and a base unit at the hospital-expert's site, enhances intensive health care provision by giving a mobile base unit to the ICU doctor while the telemedicine unit remains at the ICU patient site and enables home telemonitoring, by installing the telemedicine unit at the patient's home while the base unit remains at the physician's office or hospital. The system allows the transmission of vital biosignals (3–12 lead ECG, SPO2, NIBP, IBP, Temp) and still images of the patient. The transmission is performed through GSM mobile telecommunication network, through satellite links (where GSM is not available) or through Plain Old Telephony Systems (POTS) where available. Using this device a specialist doctor can telematically "move" to the patient's site and instruct unspecialized personnel when handling an emergency or telemonitoring case. Due to the need of storing and archiving of all data interchanged during the telemedicine sessions, we have equipped the consultation site with a multimedia database able to store and manage the data collected by the system. The performance of the system has been technically tested over several telecommunication means; in addition the system has been clinically validated in three different countries using a standardized medical protocol.
doi:10.1186/1475-925X-2-7
PMCID: PMC153497  PMID: 12694629
Emergency Health Care; Telemedicine; GSM; Satellite
18.  The primary care clinic as a setting for continuing medical education: program description 
The Mexican Institute of Social Security (IMSS) is Mexico's largest state-financed health care system, providing care to 50 million people. This system comprises 1450 family medicine clinics staffed by 14 000 family physicians, as well as 240 secondary care hospitals and 10 tertiary care medical centres. We developed a program of continuing medical education (CME) for IMSS family physicians. The program had 4 stages, which were completed over a 7-month period: development of clinical guidelines, training of clinical instructors, an educational intervention (consisting of interactive workshops, individual tutorials and peer group sessions), and evaluation of both physicians' performance and patients' health status. The pilot study was conducted in an IMSS family medicine clinic providing care to 45 000 people; 20 family physicians and 4 clinical instructors participated. The 2 main reasons for visits to IMSS family medicine clinics are acute respiratory infections and type 2 diabetes mellitus. Therefore, patients being treated at the clinic for either of these illnesses were included in the study. The sources of data were interviews with physicians and patients, clinical records and written prescriptions. A 1-group pretest–posttest design was used to compare physicians' performance in treating the 2 illnesses of interest. We found that the daily activities of the clinic could be reorganized to accommodate the CME program and that usual provision of health care services was maintained. Physicians accepted and participated actively in the program, and their performance improved over the course of the study. We conclude that this CME strategy is feasible, is acceptable to family physicians and may improve the quality of health care provided at IMSS primary care facilities. The effectiveness and sustainability of the strategy should be measured through an evaluative study.
PMCID: PMC80340  PMID: 11107467
19.  Deported Mexican migrants: health status and access to care 
Revista de Saúde Pública  2014;48(3):478-485.
OBJECTIVE
To describe the health status and access to care of forced-return Mexican migrants deported through the Mexico-United States border and to compare it with the situation of voluntary-return migrants.
METHODS
Secondary data analysis from the Survey on Migration in Mexico’s Northern Border from 2012. This is a continuous survey, designed to describe migration flows between Mexico and the United States, with a mobile-population sampling design. We analyzed indicators of health and access to care among deported migrants, and compare them with voluntary-return migrants. Our analysis sample included 2,680 voluntary-return migrants, and 6,862 deportees. We employ an ordinal multiple logistic regression model, to compare the adjusted odds of having worst self-reported health between the studied groups.
RESULTS
As compared to voluntary-return migrants, deportees were less likely to have medical insurance in the United States (OR = 0.05; 95%CI 0.04;0.06). In the regression model a poorer self-perceived health was found to be associated with having been deported (OR = 1.71, 95%CI 1.52;1.92), as well as age (OR = 1.03, 95%CI 1.02;1.03) and years of education (OR = 0.94 95%CI 0.93;0.95).
CONCLUSIONS
According to our results, deportees had less access to care while in the United States, as compared with voluntary-return migrants. Our results also showed an independent and statistically significant association between deportation and having poorer self-perceived health. To promote the health and access to care of deported Mexican migrants coming back from the United States, new health and social policies are required.
doi:10.1590/S0034-8910.2014048005150
PMCID: PMC4203084  PMID: 25119943
Emigration and Immigration; Mexico; United States; Health Services Accessibility; Health Evaluation; Health Inequalities
20.  Neurocysticercosis, a Persisting Health Problem in Mexico 
Background
The ongoing epidemiological transition in Mexico minimizes the relative impact of neurocysticercosis (NC) on public health. However, hard data on the disease frequency are not available.
Methodology
All clinical records from patients admitted in the Instituto Nacional de Neurologia y Neurocirugia (INNN) at Mexico City in 1994 and 2004 were revised. The frequencies of hospitalized NC patients in neurology, neurosurgery and psychiatry services, as well as NC mortality from 1995 through 2009, were retrieved. Statistical analyses were made to evaluate possible significant differences in frequencies of NC patients' admission between 1994 and 2004, and in yearly frequencies of NC patients' hospitalization and death between 1995 and 2009.
Principal Findings
NC frequency in INNN is not significantly different in 1994 and 2004. Between these two years, clinical severity of the cases diminished and the proportion of patients living in Mexico City increased. Yearly frequencies of hospitalization in neurology and psychiatry services were stable, while frequencies of hospitalization in neurosurgery service and mortality significantly decreased between 1995 and 2009.
Conclusions
Our findings show a stable tendency of hospital cases during the last decade that should encourage to redouble efforts to control this ancient disease.
Author Summary
Human neurocysticercosis is a severe parasitic disease caused by the installation of Taenia solium larvae in the central nervous system. Neurocysticercosis is still deeply rooted in Latin-America, Africa and Asia, where it develops its complete life cycle promoted by poor sanitary conditions. It is also emerging in developed countries due to human migration. Although hard data on the evolution of the disease incidence in endemic countries are lacking, its presence is being obscured by the growth of degenerative and metabolic diseases, creating the illusion of having disappeared.
In this article, we show that neurocysticercosis frequency has not significantly changed between 1994 and 2009 among patients attending the Instituto Nacional de Neurología y Neurocirugía, Mexico City, the principal Mexican neurological center. We also show that clinical severity of the cases diminished during this period, associated with the higher proportion of neurocysticercotic patients from Mexico City rather than from the states, where local neurological facilities have improved. These results show that neurocysticercosis is still relevant in México, and that more effective efforts should be put toward its eradication.
doi:10.1371/journal.pntd.0000805
PMCID: PMC2927420  PMID: 20808759
21.  The Severity of Pandemic H1N1 Influenza in the United States, from April to July 2009: A Bayesian Analysis 
PLoS Medicine  2009;6(12):e1000207.
Marc Lipsitch and colleagues use complementary data from two US cities, Milwaukee and New York City, to assess the severity of pandemic (H1N1) 2009 influenza in the United States.
Background
Accurate measures of the severity of pandemic (H1N1) 2009 influenza (pH1N1) are needed to assess the likely impact of an anticipated resurgence in the autumn in the Northern Hemisphere. Severity has been difficult to measure because jurisdictions with large numbers of deaths and other severe outcomes have had too many cases to assess the total number with confidence. Also, detection of severe cases may be more likely, resulting in overestimation of the severity of an average case. We sought to estimate the probabilities that symptomatic infection would lead to hospitalization, ICU admission, and death by combining data from multiple sources.
Methods and Findings
We used complementary data from two US cities: Milwaukee attempted to identify cases of medically attended infection whether or not they required hospitalization, while New York City focused on the identification of hospitalizations, intensive care admission or mechanical ventilation (hereafter, ICU), and deaths. New York data were used to estimate numerators for ICU and death, and two sources of data—medically attended cases in Milwaukee or self-reported influenza-like illness (ILI) in New York—were used to estimate ratios of symptomatic cases to hospitalizations. Combining these data with estimates of the fraction detected for each level of severity, we estimated the proportion of symptomatic patients who died (symptomatic case-fatality ratio, sCFR), required ICU (sCIR), and required hospitalization (sCHR), overall and by age category. Evidence, prior information, and associated uncertainty were analyzed in a Bayesian evidence synthesis framework. Using medically attended cases and estimates of the proportion of symptomatic cases medically attended, we estimated an sCFR of 0.048% (95% credible interval [CI] 0.026%–0.096%), sCIR of 0.239% (0.134%–0.458%), and sCHR of 1.44% (0.83%–2.64%). Using self-reported ILI, we obtained estimates approximately 7–9× lower. sCFR and sCIR appear to be highest in persons aged 18 y and older, and lowest in children aged 5–17 y. sCHR appears to be lowest in persons aged 5–17; our data were too sparse to allow us to determine the group in which it was the highest.
Conclusions
These estimates suggest that an autumn–winter pandemic wave of pH1N1 with comparable severity per case could lead to a number of deaths in the range from considerably below that associated with seasonal influenza to slightly higher, but with the greatest impact in children aged 0–4 and adults 18–64. These estimates of impact depend on assumptions about total incidence of infection and would be larger if incidence of symptomatic infection were higher or shifted toward adults, if viral virulence increased, or if suboptimal treatment resulted from stress on the health care system; numbers would decrease if the total proportion of the population symptomatically infected were lower than assumed.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Every winter, millions of people catch influenza—a viral infection of the airways—and about half a million people die as a result. In the US alone, an average of 36,000 people are thought to die from influenza-related causes every year. These seasonal epidemics occur because small but frequent changes in the virus mean that an immune response produced one year provides only partial protection against influenza the next year. Occasionally, influenza viruses emerge that are very different and to which human populations have virtually no immunity. These viruses can start global epidemics (pandemics) that kill millions of people. Experts have been warning for some time that an influenza pandemic is long overdue and in, March 2009, the first cases of influenza caused by a new virus called pandemic (H1N1) 2009 (pH1N1; swine flu) occurred in Mexico. The virus spread rapidly and on 11 June 2009, the World Health Organization declared that a global pandemic of pH1N1 influenza was underway. By the beginning of November 2009, more than 6,000 people had died from pH1N1 influenza.
Why Was This Study Done?
With the onset of autumn—drier weather and the return of children to school help the influenza virus to spread—pH1N1 cases, hospitalizations, and deaths in the Northern Hemisphere have greatly increased. Although public-health officials have been preparing for this resurgence of infection, they cannot be sure of its impact on human health without knowing more about the severity of pH1N1 infections. The severity of an infection can be expressed as a case-fatality ratio (CFR; the proportion of cases that result in death), as a case-hospitalization ratio (CHR; the proportion of cases that result in hospitalization), and as a case-intensive care ratio (CIR; the proportion of cases that require treatment in an intensive care unit). Because so many people have been infected with pH1N1 since it emerged, the numbers of cases and deaths caused by pH1N1 infection are not known accurately so these ratios cannot be easily calculated. In this study, the researchers estimate the severity of pH1N1 influenza in the US between April and July 2009 by combining data on pH1N1 infections from several sources using a statistical approach known as Bayesian evidence synthesis.
What Did the Researchers Do and Find?
By using data on medically attended and hospitalized cases of pH1N1 infection in Milwaukee and information from New York City on hospitalizations, intensive care use, and deaths, the researchers estimate that the proportion of US cases with symptoms that died (the sCFR) during summer 2009 was 0.048%. That is, about 1 in 2,000 people who had symptoms of pH1N1 infection died. The “credible interval” for this sCFR, the range of values between which the “true” sCFR is likely to lie, they report, is 0.026%–0.096% (between 1 in 4,000 and 1 in 1,000 deaths for every symptomatic case). About 1 in 400 symptomatic cases required treatment in intensive care, they estimate, and about 1 in 70 symptomatic cases required hospital admission. When the researchers used a different approach to estimate the total number of symptomatic cases—based on New Yorkers' self-reported incidence of influenza-like-illness from a telephone survey—their estimates of pH1N1 infection severity were 7- to 9-fold lower. Finally, they report that the sCFR and the sCIR were highest in people aged 18 or older and lowest in children aged 5–17 years.
What Do These Findings Mean?
Many uncertainties (for example, imperfect detection and reporting) can affect estimates of influenza severity. Even so, the findings of this study suggest that an autumn–winter pandemic wave of pH1N1 will have a death toll only slightly higher than or considerably lower than that caused by seasonal influenza in an average year, provided pH1N1 continues to behave as it did during the summer. Similarly, the estimated burden on hospitals and intensive care facilities ranges from somewhat higher than in a normal influenza season to considerably lower. The findings of this study also suggest that, unlike seasonal influenza, which kills mainly elderly adults, a high proportion of deaths from pH1N1infection will occur in nonelderly adults, a shift in age distribution that has been seen in previous pandemics. With these estimates in hand and with continued close monitoring of the pandemic, public-health officials should now be in a better position to plan effective strategies to deal with the pH1N1 pandemic.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000207.
The US Centers for Disease Control and Prevention provides information about influenza for patients and professionals, including specific information on pandemic H1N1 (2009) influenza
Flu.gov, a US government Web site, provides access to information on H1N1, avian and pandemic influenza
The World Health Organization provides information on seasonal influenza and has detailed information on pandemic H1N1 (2009) influenza (in several languages)
The UK Health Protection Agency provides information on pandemic influenza and on pandemic H1N1 (2009) influenza
More information for patients about H1N1 influenza is available through Choices, an information resource provided by the UK National Health Service
doi:10.1371/journal.pmed.1000207
PMCID: PMC2784967  PMID: 19997612
22.  A Qualitative Study of the Work Environments of Mexican Nurses 
Background
Studies of the nursing work environment are increasingly common in developed countries, but few exist in developing countries. Because of resource differences between the two contexts, researchers need to clarify what aspects of the work environments are similar and different.
Objectives
To study the perspectives of Mexican nurses about their work environments to determine similarities and differences to results from developed world studies.
Design
A secondary, directed content analysis of qualitative data from 46 Spanish language interviews using workplace-oriented themes
Setting
Purposively selected Mexican states from four regions of the country that reflect the country’s socioeconomic differences.
Participants
Practicing Mexican nurses with at least one year of clinical experience and currently working in nursing. Participants were recruited through convenience and snowball sampling techniques.
Methods
Initial data collection occurred in 2006 and 2008 during a broader study about professionalization processes that occurred in Mexican nursing between 1980 and 2005. The secondary, directed content analysis focused on an in-depth exploration of a central theme that emerged from the two original studies: The Workplace. The directed content analysis used themes from the global nursing work environment literature to structure the analysis: Professional relationships, organizational administrative practices, and quality of care and services.
Results
The three themes from the global literature were relevant for the Mexican context and a new one emerged related to hiring practices. By category, the same factors that created positive or negative perceptions of the work environment matched findings from other international studies conducted in developed countries. The descriptors of the category, however, had different conceptual meanings that illustrate the health system challenges in Mexico.
Conclusions
Findings from this study suggest that studies that seek to measure nursing work environments will most likely apply in Mexico and other Latin American or middle-income countries. Instruments designed to measure the work environment of nurses in these countries may prove relevant in those contexts, but require careful adaptation and systematic translations to ensure it.
doi:10.1016/j.ijnurstu.2012.02.001
PMCID: PMC3383907  PMID: 22386989
Cross-language research; Mexico; nurses; secondary analysis; qualitative research; work-environment
23.  Measuring Tijuana residents' choice of Mexican or U.S. health care services. 
Public Health Reports  1990;105(6):575-583.
There is growing concern that the indigent health care burden in the southwestern United States may be caused partly by Mexican residents who cross the border to use U.S. health services. This article describes the first attempt to measure the extent of this use by border residents. It also compares factors associated with their use of health care services in both the United States and Mexico. Data were obtained from a household survey conducted in Tijuana, Mexico, near the California border, using a random, stratified analytic sample of 660 households that included a total of 2,954 persons. The dependent variables--extent and volume of contacts with health professionals--were examined according to sociodemographic characteristics, insurance coverage, payment modality, type of visit, and health care setting. The results indicate that 40.3 percent of the Tijuana population used health services exclusively in Mexico during a 6-month period, compared with only 2.5 percent who used services in the United States. Of the Mexican users of U.S. services, the largest proportion appeared to be older people, lawful permanent residents or citizens of the United States who are living in Mexico, and persons from high- or middle-income sectors. In addition to the low level of use of U.S. health services, the findings show that more than 84 percent of the visits were to providers in the private sector and, for 59 percent of the visits, a fee for services was implied. Overall, this border population does not seem to be a drain on the U.S. public health system.(ABSTRACT TRUNCATED AT 250 WORDS)
PMCID: PMC1580173  PMID: 2124358
24.  A Comparison of the Health of Older Hispanics in the United States and Mexico 
Journal of aging and health  2008;20(1):3-31.
Objectives
This study compares various dimensions of physical and emotional health between older Mexican-origin individuals in the United States and in Mexico.
Method
The samples are drawn from the Mexican Health and Aging Study (MHAS) and the Hispanic Established Epidemiologic Study of the Elderly (H-EPESE) and include 3,875 Mexican residents with no history of residence in the United States and 2,734 Mexican-origin individuals 65 and older who live in the southwestern United States.
Results
Both immigrant and native-born Mexican-origin elders in the United States report more chronic conditions than elderly Mexicans, but they report fewer symptoms of psychological distress. Longer residence in the United States is associated with higher body mass index scores.
Discussion
The discussion addresses the possibility that access to care influences reports of diagnosed conditions and touches on issues of comparability in cross-cultural research and the difficulty in clearly distinguishing cultural and system-level factors in the production and measurement of health.
doi:10.1177/0898264307309924
PMCID: PMC4000710  PMID: 18252935
Hispanic health; older Mexican Americans; health measurement; Hispanic Established Epidemiologic Study of the Elderly; Mexican Health and Aging Study
25.  Immigration and Suicidal Behavior Among Mexicans and Mexican Americans 
American journal of public health  2009;99(4):728-733.
Objectives
We examined migration to the United States as a risk factor for suicidal behavior among people of Mexican origin.
Methods
We pooled data from 2 nationally representative surveys in the United States (2001–2003; n=1284) and Mexico (2001–2002; n=5782). We used discrete time survival models to account for time-varying and time-invariant characteristics, including psychiatric disorders.
Results
Risk for suicidal ideation was higher among Mexicans with a family member in the United States (odds ratio [OR]=1.50; 95% confidence interval [CI]=1.06, 2.11), Mexican-born immigrants who arrived in the United States at 12 years or younger (OR=1.84; 95% CI=1.09, 3.09), and US-born Mexican Americans (OR=1.56; 95% CI=1.03, 2.38) than among Mexicans with neither a history of migration to the United States nor a family member currently living there. Risk for suicide attempts was also higher among Mexicans with a family member in the United States (OR=1.68; 95% CI=1.13, 2.52) and US-born Mexican Americans (OR=1.97; 95% CI=1.06, 3.65). Selection bias caused by differential migration or differential return migration of persons at higher risk of suicidal ideation or attempt did not account for these findings.
Conclusions
Public health efforts should focus on the impact of Mexico–US migration on family members of migrants and on US-born Mexican Americans.
doi:10.2105/AJPH.2008.135160
PMCID: PMC2661474  PMID: 19150909

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