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1.  Inequality, Poverty, and Material Deprivation in New and Old Members of European Union 
Croatian medical journal  2007;48(5):636-652.
To analyze the main indicators of income inequality, objective and subjective poverty, material deprivation, and the role of public social transfers in the reduction of poverty in 15 old and 10 new member states of the European Union (EU), undergoing post-communist socio-economic transition, as well as in Croatia, a candidate EU country.
Objective poverty rates, poverty reduction rates, poverty thresholds in purchasing power standards (PPS), total social expenditure, inequality indicators, and risks of poverty according to demographics were calculated using the data from the Eurostat databases (in particular, Household Budget Survey). For Croatia, Central Bureau of Statistics first releases on poverty indicators were used, as well as database of the Ministry of Finance (social expenditure). Subjective poverty rates and non-monetary deprivation index were calculated using the European Quality of Life Survey, which was carried out in 2003 in EU countries and in 2006 in Croatia.
According to the indicators of income inequality and objective poverty, there was a divide among old EU member states (EU15), with UK, Ireland and South European countries having higher and Continental and Nordic countries lower indicators of inequality and poverty. Among new member states (NMS10), Baltic countries and Poland had the highest and Slovenia and the Czech Republic the lowest indicators of inequality and poverty. In all EU15 countries, except Greece, subjective poverty rates were lower than objective ones, whereas in all NMS10 countries the levels of subjective poverty were much higher than those of objective poverty. With some exceptions, NMS10 countries had low or even decreasing social expenditures. The share of respondents who were deprived of more than 50% of items was 6 times higher in the NMS10 than in the EU15 countries. When standard of living was measured by income inequality, relative poverty rates, poverty reduction rates, total social protection expenditures, and non-monetary deprivation, only Slovenia, the Czech Republic, and Hungary, out of the NMS10, were in the upper half of the distribution, while Croatia had a medium position among NMS10 states.
Our analysis demonstrated that poverty in countries undergoing post-socialist socioeconomic transition is widespread and could seriously limit human development. Continual research and monitoring of different aspects of poverty is needed for setting appropriate policies across the EU to effectively combat poverty and social exclusion and to promote convergence process.
PMCID: PMC2205970  PMID: 17948950
2.  Sleep deprivation amplifies reactivity of brain reward networks, biasing the appraisal of positive emotional experiences 
Appropriate interpretation of pleasurable, rewarding experiences favors decisions that enhance survival. Conversely, dysfunctional affective brain processing can lead to life-threatening risk behaviors (e.g. addiction) and emotion imbalance (e.g. mood disorders). The state of sleep deprivation continues to be associated with maladaptive emotional regulation, leading to exaggerated neural and behavioral reactivity to negative, aversive experiences. However, such detrimental consequences are paradoxically aligned with the perplexing antidepressant benefit of sleep deprivation, elevating mood in a proportion of patients with major depression. Nevertheless, it remains unknown how sleep loss alters the dynamics of brain and behavioral reactivity to rewarding, positive emotional experiences. Using fMRI, here we demonstrate that sleep deprivation amplifies reactivity throughout human mesolimbic reward brain networks in response to pleasure-evoking stimuli. In addition, this amplified reactivity was associated with enhanced connectivity in early primary visual processing pathways and extended limbic regions, yet with a reduction in coupling with medial- and orbito-frontal regions. These neural changes were accompanied by a biased increase in the number of emotional stimuli judged as pleasant in the sleep-deprived group, the extent of which exclusively correlated with activity in mesolimbic regions. Together, these data support a view that sleep deprivation is not only associated with enhanced reactivity towards negative stimuli, but imposes a bi-directional nature of affective imbalance, associated with amplified reward-relevant reactivity towards pleasure-evoking stimuli also. Such findings may offer a neural foundation on which to consider interactions between sleep loss and emotional reactivity in a variety of clinical mood disorders.
PMCID: PMC3086142  PMID: 21430147
Sleep Deprivation; Positive Emotion; Reward; Brain Reactivity
3.  Drivers of Inequality in Millennium Development Goal Progress: A Statistical Analysis 
PLoS Medicine  2010;7(3):e1000241.
David Stuckler and colleagues examine the impact of the HIV and noncommunicable disease epidemics on low-income countries' progress toward the Millennium Development Goals for health.
Many low- and middle-income countries are not on track to reach the public health targets set out in the Millennium Development Goals (MDGs). We evaluated whether differential progress towards health MDGs was associated with economic development, public health funding (both overall and as percentage of available domestic funds), or health system infrastructure. We also examined the impact of joint epidemics of HIV/AIDS and noncommunicable diseases (NCDs), which may limit the ability of households to address child mortality and increase risks of infectious diseases.
Methods and Findings
We calculated each country's distance from its MDG goals for HIV/AIDS, tuberculosis, and infant and child mortality targets for the year 2005 using the United Nations MDG database for 227 countries from 1990 to the present. We studied the association of economic development (gross domestic product [GDP] per capita in purchasing-power-parity), the relative priority placed on health (health spending as a percentage of GDP), real health spending (health system expenditures in purchasing-power-parity), HIV/AIDS burden (prevalence rates among ages 15–49 y), and NCD burden (age-standardised chronic disease mortality rates), with measures of distance from attainment of health MDGs. To avoid spurious correlations that may exist simply because countries with high disease burdens would be expected to have low MDG progress, and to adjust for potential confounding arising from differences in countries' initial disease burdens, we analysed the variations in rates of change in MDG progress versus expected rates for each country. While economic development, health priority, health spending, and health infrastructure did not explain more than one-fifth of the differences in progress to health MDGs among countries, burdens of HIV and NCDs explained more than half of between-country inequalities in child mortality progress (R2-infant mortality  = 0.57, R2-under 5 mortality  = 0.54). HIV/AIDS and NCD burdens were also the strongest correlates of unequal progress towards tuberculosis goals (R2 = 0.57), with NCDs having an effect independent of HIV/AIDS, consistent with micro-level studies of the influence of tobacco and diabetes on tuberculosis risks. Even after correcting for health system variables, initial child mortality, and tuberculosis diseases, we found that lower burdens of HIV/AIDS and NCDs were associated with much greater progress towards attainment of child mortality and tuberculosis MDGs than were gains in GDP. An estimated 1% lower HIV prevalence or 10% lower mortality rate from NCDs would have a similar impact on progress towards the tuberculosis MDG as an 80% or greater rise in GDP, corresponding to at least a decade of economic growth in low-income countries.
Unequal progress in health MDGs in low-income countries appears significantly related to burdens of HIV and NCDs in a population, after correcting for potentially confounding socioeconomic, disease burden, political, and health system variables. The common separation between NCDs, child mortality, and infectious syndromes among development programs may obscure interrelationships of illness affecting those living in poor households—whether economic (e.g., as money spent on tobacco is lost from child health expenditures) or biological (e.g., as diabetes or HIV enhance the risk of tuberculosis).
Please see later in the article for the Editors' Summary
Editors' Summary
In 2000, 189 countries adopted the United Nations (UN) Millennium Declaration, which commits the world to the eradication of extreme poverty by 2015. The Declaration lists eight Millennium Development Goals (MDGs), 21 quantifiable targets, and 60 indicators of progress. So, for example, MDG 4 aims to reduce child mortality (deaths). The target for this goal is to reduce the number of children who die each year before they are five years old (the under-five mortality rate) to two-thirds of its 1990 value by 2015. Indicators of progress toward this goal include the under-five mortality rate and the infant mortality rate. Because poverty and ill health are inextricably linked—ill health limits the ability of individuals and nations to improve their economic status, and poverty contributes to the development of many illnesses—two other MDGs also tackle public health issues. MDG 5 sets a target of reducing maternal mortality by three-quarters of its 1990 level by 2015. MDG 6 aims to halt and begin to reverse the spread of HIV/AIDS, malaria, and other major diseases such as tuberculosis by 2015.
Why Was This Study Done?
Although progress has been made toward achieving the MDGs, few if any of the targets are likely to be met by 2015. Worryingly, low-income countries are falling furthest behind their MDG targets. For example, although child mortality has been declining globally, in many poor countries there has been little or no progress. What is the explanation for this and other inequalities in progress toward the health MDGs? Some countries may simply lack the financial resources needed to combat epidemics or may allocate only a low proportion of their gross domestic product (GDP) to health. Alternatively, money allocated to health may not always reach the people who need it most because of an inadequate health infrastructure. Finally, coexisting epidemics may be hindering progress toward the MDG health targets. Thus, the spread of HIV/AIDS may be hindering attempts to limit the spread of tuberculosis because HIV infection increases the risk of active tuberculosis, and ongoing epidemics of diabetes and other noncommunicable diseases (NCDs) may be affecting the attainment of health MDGs by diverting scarce resources. In this study, the researchers investigate whether any of these possibilities is driving the inequalities in MDG progress.
What Did the Researchers Do and Find?
The researchers calculated how far 227 countries were from their MDG targets for HIV, tuberculosis, and infant and child mortality in 2005 using information collected by the UN. They then used statistical methods to study the relationship between this distance and economic development (GDP per person), health spending as a proportion of GDP (health priority), actual health system expenditures, health infrastructure, HIV burden, and NCD burden in each country. Economic development, health priority, health spending, and health infrastructure explained no more than one-fifth of the inequalities in progress toward health MDGs. By contrast, the HIV and NCD burdens explained more than half of inequalities in child mortality progress and were strongly associated with unequal progress toward tuberculosis goals. Furthermore, the researchers calculated that a 1% reduction in the number of people infected with HIV or a 10% reduction in rate of deaths from NCDs in a population would have a similar impact on progress toward the tuberculosis MDG target as a rise in GDP corresponding to at least a decade of growth in low-income countries.
What Do These Findings Mean?
These findings are limited by the quality of the available data on health indicators in low-income countries and, because the researchers used country-wide data, their findings only reveal possible drivers of inequalities in progress toward MDGs in whole countries and may mask drivers of within-country inequalities. Nevertheless, as one of the first attempts to analyze the determinants of global inequalities in progress toward the health MDGs, these findings have important implications for global health policy. Most importantly, the finding that unequal progress is related to the burdens of HIV and NCDs in populations suggests that programs designed to achieve health MDGs must consider all the diseases and factors that can trap households in vicious cycles of illness and poverty, especially since the achievement of feasible reductions in NCDs in low-income countries could greatly enhance progress towards health MDGs.
Additional Information
Please access these Web sites via the online version of this summary at
The United Nations Millennium Development Goals website provides detailed information about the Millennium Declaration, the MDGs, their targets and their indicators
The Millennium Development Goals Report 2009 and its progress chart provide an up-to-date assessment of progress towards the MDGs
The World Health Organization provides information about poverty and health and health and development
PMCID: PMC2830449  PMID: 20209000
4.  Are neighbourhood food resources distributed inequitably by income and race in the USA? Epidemiological findings across the urban spectrum 
BMJ Open  2012;2(2):e000698.
Many recent policies focus on socioeconomic inequities in availability of healthy food stores and restaurants. Yet understanding of how socioeconomic inequities vary across neighbourhood racial composition and across the range from rural to urban settings is limited, largely due to lack of large, geographically and socio-demographically diverse study populations. Using a national sample, the authors examined differences in neighbourhood food resource availability according to neighbourhood-level poverty and racial/ethnic population in non-urban, low-density urban and high-density urban areas.
Cross-sectional data from an observational cohort study representative of the US middle and high school-aged population in 1994 followed into young adulthood.
Using neighbourhood characteristics of participants in the National Longitudinal Study of Adolescent Health (Wave III, 2001–2002; n=13 995 young adults aged 18–28 years representing 7588 US block groups), the authors examined associations between neighbourhood poverty and race/ethnicity with neighbourhood food resource availability in urbanicity-stratified multivariable linear regression.
Primary and secondary outcome measures
Neighbourhood availability of grocery/supermarkets, convenience stores and fast-food restaurants (measured as number of outlets per 100 km roadway).
Neighbourhood race and income disparities were most pronounced in low-density urban areas, where high-poverty/high-minority areas had lower availability of grocery/supermarkets (β coefficient (β)=–1.91, 95% CI –2.73 to –1.09) and convenience stores (β=–2.38, 95% CI –3.62 to –1.14) and greater availability of fast-food restaurants (β=4.87, 95% CI 2.26 to 7.48) than low-poverty/low-minority areas. However, in high-density urban areas, high-poverty/low-minority neighbourhoods had comparatively greater availability of grocery/supermarkets (β=8.05, 95% CI 2.52 to 13.57), convenience stores (β=2.89, 95% CI 0.64 to 5.14) and fast-food restaurants (β=4.03, 95% CI 1.97 to 6.09), relative to low-poverty/low-minority areas.
In addition to targeting disproportionate fast-food availability in disadvantaged dense urban areas, our findings suggest that policies should also target disparities in grocery/supermarket and fast-food restaurant availability in low-density areas.
Article summary
Article focus
Using national data, we examined whether neighbourhood food resource availability exhibits joint race and socioeconomic inequities across levels of urbanicity.
Key messages
Socio-demographic inequities in neighbourhood food resource availability were most pronounced in low-density urban (largely suburban) areas.
In high-density urban areas, higher neighbourhood poverty was associated with greater availability of all food resources.
Whereas policy has focused on dense urban settings, less urban areas might also benefit from policies addressing food access.
Strengths and limitations of this study
While business records provide comparable data across the USA, these data may contain error and do not indicate availability of specific foods.
National coverage enabled examination of the joint role of neighbourhood race and socioeconomic status across urban strata within a single study.
PMCID: PMC3329604  PMID: 22505308
5.  The brain correlates of the effects of monetary and verbal rewards on intrinsic motivation 
Apart from everyday duties, such as doing the laundry or cleaning the house, there are tasks we do for pleasure and enjoyment. We do such tasks, like solving crossword puzzles or reading novels, without any external pressure or force; instead, we are intrinsically motivated: we do the tasks because we enjoy doing them. Previous studies suggest that external rewards, i.e., rewards from the outside, affect the intrinsic motivation to engage in a task: while performance-based monetary rewards are perceived as controlling and induce a business-contract framing, verbal rewards praising one's competence can enhance the perceived self-determination. Accordingly, the former have been shown to decrease intrinsic motivation, whereas the latter have been shown to increase intrinsic motivation. The present study investigated the neural processes underlying the effects of monetary and verbal rewards on intrinsic motivation in a group of 64 subjects applying functional magnetic resonance imaging (fMRI). We found that, when participants received positive performance feedback, activation in the anterior striatum and midbrain was affected by the nature of the reward; compared to a non-rewarded control group, activation was higher while monetary rewards were administered. However, we did not find a decrease in activation after reward withdrawal. In contrast, we found an increase in activation for verbal rewards: after verbal rewards had been withdrawn, participants showed a higher activation in the aforementioned brain areas when they received success compared to failure feedback. We further found that, while participants worked on the task, activation in the lateral prefrontal cortex was enhanced after the verbal rewards were administered and withdrawn.
PMCID: PMC4166960  PMID: 25278834
intrinsic motivation; crowding-out; monetary rewards; verbal rewards; fMRI
6.  Empowering the Impoverished and Reducing Healthcare Costs 
Global Advances in Health and Medicine  2014;3(Suppl 1):BPA15.
Socioeconomic disadvantage is a major risk factor for poor health and a consistent contributor to chronic stress, both of which are disempowering to individuals and communities. Poverty has been linked to a higher prevalence of many health conditions, including increased risk of chronic disease, injury, deprived infant development, anxiety, depression, premature death, and the negative impact of allostatic load associated with chronic stress. With the rising costs of healthcare, there is an urgent and ongoing need for effective strategies for the impoverished to diminish the negative impact of the stress response and enhance their level of empowerment.
Individuals associated with a community-based organization that assists impoverished individuals to move toward self-sufficiency were invited to attend a HeartMath (HM) two-session workshop series (4 weeks apart), and an additional discussion-only session was scheduled 4 weeks after the second session. Participants completed Personal and Organizational Quality Assessments (POQAs) at both workshop sessions to gather pre- and post-intervention data. Each session 1 participant received a Quiet Joy CD and was asked to practice the techniques that they learned between sessions 1 and 2. A third session was scheduled 4 weeks after session 2 as a check-in with participants to determine if they continued to use the HeartMath techniques and for them to share their experiences as a result of exposure to the information.
Twenty individuals participated in workshop session 1; 14 participated in workshop session 2; and 11 individuals attended session 3. Although an equal-pair comparison was not possible, pre and post POQA analysis results demonstrated a general improvement in emotional well-being and reduction in stress symptoms for the group. However, there was a slight but notable reduction in two areas: positive outlook and gratitude. Individuals showed reduced symptoms in the six General Health Stress Symptoms categories, and the Group Average Stress Score was reduced by 40 on the post assessment. In the third, group-discussion-only session, participants shared anecdotally their experiences with emotion regulation and stress transformation since participation in the two-session workshop. The majority reported that they continued to use the HeartMath techniques and generally reported that they felt at ease more often and, in most cases, were better able to regulate their stress responses associated with the challenges of their lower socioeconomic status.
Although HeartMath cannot be solely depended upon to resolve all matters associated with poverty, it is believed that it holds potential as an additional resource for those facing the daily stressors and the negative biopsychoemotional impacts associated with it. Consistent practice and application of the HeartMath techniques hold potential to enhance people's emotion-regulation ability, to build and sustain psychophysiological resilience, and to increase some level of control in their lives. Thus, HeartMath is being promoted as an intermediate pathway to improve physical health and psycho-emotional well-being, increase individual and community empowerment, and ultimately reduce healthcare costs among those of lower socioeconomic status.
PMCID: PMC3923292
Personal and Organizational Quality Assessments; biofeedback; stress reduction; HeartMath
7.  Impact of predisposing, enabling, and need factors in accessing preventive medical care among U.S. children: results of the national survey of children's health 
Preventive care in the United States has been a priority, especially for children under 18 years of age. The objective of this analysis was to determine which predisposing, enabling, and need factors affect access to preventive health care for children.
Data were obtained from the National Survey of Children's Health (NSCH), a cross-sectional study of children in the United States. The current analysis examined whether predisposing, enabling, and need factors included in Andersen's Socio-Behavioral Model significantly affect having received preventive medical care among children 3–17 years of age. Logistic regression was used to compute odds ratios and 95% confidence intervals.
63,924 out of 85,151 subjects were reported as having received preventive medical care. After stratifying by geographical region, the following factors were significant for predicting having received preventive care. Age was negatively associated with having received care in all four regions. Household education of less than a college degree and being white (compared to black) were negatively associated with having received care in the Northeast, Midwest, and South. Having fewer than 4 children was negatively associated in Northeast but positively associated in the West with having received care. Being male, having less than 3 children in the household, having less than 3 adults in the household, and being Hispanic were positively associated with having received care in the West only. Not having insurance and having a lower socioeconomic status were negatively associated with having received care; while, having a personal doctor or nurse was positively associated in all four regions. Primary language other than English was negatively associated with having received care in the Northeast only. Currently needing medicine was also positively associated with having received care in all four regions; while, having limited abilities to do things was positively associated in the West only.
Older children whose family resides in Northeast, Midwest, and South regions with low household education and poverty levels experience insufficient preventive health care. Medicaid or SCHIP coverage should be expanded for children who are still uninsured. For children in the West, gender, family size, ethnicity, and their ability to do things should also be considered when providing assistance for receiving preventive care.
PMCID: PMC2615756  PMID: 19061524
8.  The Rewarding Aspects of Music Listening Are Related to Degree of Emotional Arousal 
PLoS ONE  2009;4(10):e7487.
Listening to music is amongst the most rewarding experiences for humans. Music has no functional resemblance to other rewarding stimuli, and has no demonstrated biological value, yet individuals continue listening to music for pleasure. It has been suggested that the pleasurable aspects of music listening are related to a change in emotional arousal, although this link has not been directly investigated. In this study, using methods of high temporal sensitivity we investigated whether there is a systematic relationship between dynamic increases in pleasure states and physiological indicators of emotional arousal, including changes in heart rate, respiration, electrodermal activity, body temperature, and blood volume pulse.
Twenty-six participants listened to self-selected intensely pleasurable music and “neutral” music that was individually selected for them based on low pleasure ratings they provided on other participants' music. The “chills” phenomenon was used to index intensely pleasurable responses to music. During music listening, continuous real-time recordings of subjective pleasure states and simultaneous recordings of sympathetic nervous system activity, an objective measure of emotional arousal, were obtained.
Principal Findings
Results revealed a strong positive correlation between ratings of pleasure and emotional arousal. Importantly, a dissociation was revealed as individuals who did not experience pleasure also showed no significant increases in emotional arousal.
These results have broader implications by demonstrating that strongly felt emotions could be rewarding in themselves in the absence of a physically tangible reward or a specific functional goal.
PMCID: PMC2759002  PMID: 19834599
9.  Reinterpreting Ethnic Patterns among White and African American Men Who Inject Heroin: A Social Science of Medicine Approach 
PLoS Medicine  2006;3(10):e452.
Street-based heroin injectors represent an especially vulnerable population group subject to negative health outcomes and social stigma. Effective clinical treatment and public health intervention for this population requires an understanding of their cultural environment and experiences. Social science theory and methods offer tools to understand the reasons for economic and ethnic disparities that cause individual suffering and stress at the institutional level.
Methods and Findings
We used a cross-methodological approach that incorporated quantitative, clinical, and ethnographic data collected by two contemporaneous long-term San Francisco studies, one epidemiological and one ethnographic, to explore the impact of ethnicity on street-based heroin-injecting men 45 years of age or older who were self-identified as either African American or white. We triangulated our ethnographic findings by statistically examining 14 relevant epidemiological variables stratified by median age and ethnicity. We observed significant differences in social practices between self-identified African Americans and whites in our ethnographic social network sample with respect to patterns of (1) drug consumption; (2) income generation; (3) social and institutional relationships; and (4) personal health and hygiene. African Americans and whites tended to experience different structural relationships to their shared condition of addiction and poverty. Specifically, this generation of San Francisco injectors grew up as the children of poor rural to urban immigrants in an era (the late 1960s through 1970s) when industrial jobs disappeared and heroin became fashionable. This was also when violent segregated inner city youth gangs proliferated and the federal government initiated its “War on Drugs.” African Americans had earlier and more negative contact with law enforcement but maintained long-term ties with their extended families. Most of the whites were expelled from their families when they began engaging in drug-related crime. These historical-structural conditions generated distinct presentations of self. Whites styled themselves as outcasts, defeated by addiction. They professed to be injecting heroin to stave off “dopesickness” rather than to seek pleasure. African Americans, in contrast, cast their physical addiction as an oppositional pursuit of autonomy and pleasure. They considered themselves to be professional outlaws and rejected any appearance of abjection. Many, but not all, of these ethnographic findings were corroborated by our epidemiological data, highlighting the variability of behaviors within ethnic categories.
Bringing quantitative and qualitative methodologies and perspectives into a collaborative dialog among cross-disciplinary researchers highlights the fact that clinical practice must go beyond simple racial or cultural categories. A clinical social science approach provides insights into how sociocultural processes are mediated by historically rooted and institutionally enforced power relations. Recognizing the logical underpinnings of ethnically specific behavioral patterns of street-based injectors is the foundation for cultural competence and for successful clinical relationships. It reduces the risk of suboptimal medical care for an exceptionally vulnerable and challenging patient population. Social science approaches can also help explain larger-scale patterns of health disparities; inform new approaches to structural and institutional-level public health initiatives; and enable clinicians to take more leadership in changing public policies that have negative health consequences.
Bourgois and colleagues found that the African American and white men in their study had a different pattern of drug use and risk behaviors, adopted different strategies for survival, and had different personal histories.
Editors' Summary
There are stark differences in the health of different ethnic groups in America. For example, the life expectancy for white men is 75.4 years, but it is only 69.2 years for African-American men. The reasons behind these disparities are unclear, though there are several possible explanations. Perhaps, for example, different ethnic groups are treated differently by health professionals (with some groups receiving poorer quality health care). Or maybe the health disparities are due to differences across ethnic groups in income level (we know that richer people are healthier). These disparities are likely to persist unless we gain a better understanding of how they arise.
Why Was This Study Done?
The researchers wanted to study the health of a very vulnerable community of people: heroin users living on the streets in the San Francisco Bay Area. The health status of this community is extremely poor, and its members are highly stigmatized—including by health professionals themselves. The researchers wanted to know whether African American men and white men who live on the streets have a different pattern of drug use, whether they adopt varying strategies for survival, and whether they have different personal histories. Knowledge of such differences would help the health community to provide more tailored and culturally appropriate interventions. Physicians, nurses, and social workers often treat street-based drug users, especially in emergency rooms and free clinics. These health professionals regularly report that their interactions with street-based drug users are frustrating and confrontational. The researchers hoped that their study would help these professionals to have a better understanding of the cultural backgrounds and motivations of their drug-using patients.
What Did the Researchers Do and Find?
Over the course of six years, the researchers directly observed about 70 men living on the streets who injected heroin as they went about their usual lives (this type of research is called “participant observation”). The researchers specifically looked to see whether there were differences between the white and African American men. All the men gave their consent to be studied in this way and to be photographed. The researchers also studied a database of interviews with almost 7,000 injection drug users conducted over five years, drawing out the data on differences between white and African men. The researchers found that the white men were more likely to supplement their heroin use with inexpensive fortified wine, while African American men were more likely to supplement heroin with crack. Most of the white men were expelled from their families when they began engaging in drug-related crime, and these men tended to consider themselves as destitute outcasts. African American men had earlier and more negative contact with law enforcement but maintained long-term ties with their extended families, and these men tended to consider themselves as professional outlaws. The white men persevered less in attempting to find a vein in which to inject heroin, and so were more likely to inject the drug directly under the skin—this meant that they were more likely to suffer from skin abscesses. The white men generated most of their income from panhandling (begging for money), while the African American men generated most of their income through petty crime and/or through offering services such as washing car windows at gas stations.
What Do These Findings Mean?
Among street-based heroin users, there are important differences between white men and African American men in the type of drugs used, the method of drug use, their social backgrounds, the way in which they identify themselves, and the health risks that they take. By understanding these differences, health professionals should be better placed to provide tailored and appropriate care when these men present to clinics and emergency rooms. As the researchers say, “understanding of different ethnic populations of drug injectors may reduce difficult clinical interactions and resultant physician frustration while improving patient access and adherence to care.” One limitation of this study is that the researchers studied one specific community in one particular area of the US—so we should not assume that their findings would apply to street-based heroin users elsewhere.
Additional Information.
Please access these Web sites via the online version of this summary at
The US Centers for Disease Control (CDC) has a web page on HIV prevention among injection drug users
The World Health Organization has collected documents on reducing the risk of HIV in injection drug users and on harm reduction approaches
The International Harm Reduction Association has information relevant to a global audience on reducing drug-related harm among individuals and communities
US-focused information on harm reduction is available via the websites of the Harm Reduction Coalition and the Chicago Recovery Alliance
Canada-focused information can be found at the Street Works Web site
The Harm Reduction Journal publishes open-access articles
The CDC has a web page on eliminating racial and ethnic health disparities
The Drug Policy Alliance has a web page on drug policy in the United States
PMCID: PMC1621100  PMID: 17076569
10.  Indigenous Health and Socioeconomic Status in India 
PLoS Medicine  2006;3(10):e421.
Systematic evidence on the patterns of health deprivation among indigenous peoples remains scant in developing countries. We investigate the inequalities in mortality and substance use between indigenous and non-indigenous, and within indigenous, groups in India, with an aim to establishing the relative contribution of socioeconomic status in generating health inequalities.
Methods and Findings
Cross-sectional population-based data were obtained from the 1998–1999 Indian National Family Health Survey. Mortality, smoking, chewing tobacco use, and alcohol use were four separate binary outcomes in our analysis. Indigenous status in the context of India was operationalized through the Indian government category of scheduled tribes, or Adivasis, which refers to people living in tribal communities characterized by distinctive social, cultural, historical, and geographical circumstances.
Indigenous groups experience excess mortality compared to non-indigenous groups, even after adjusting for economic standard of living (odds ratio 1.22; 95% confidence interval 1.13–1.30). They are also more likely to smoke and (especially) drink alcohol, but the prevalence of chewing tobacco is not substantially different between indigenous and non-indigenous groups. There are substantial health variations within indigenous groups, such that indigenous peoples in the bottom quintile of the indigenous-peoples-specific standard of living index have an odds ratio for mortality of 1.61 (95% confidence interval 1.33–1.95) compared to indigenous peoples in the top fifth of the wealth distribution. Smoking, drinking alcohol, and chewing tobacco also show graded associations with socioeconomic status within indigenous groups.
Socioeconomic status differentials substantially account for the health inequalities between indigenous and non-indigenous groups in India. However, a strong socioeconomic gradient in health is also evident within indigenous populations, reiterating the overall importance of socioeconomic status for reducing population-level health disparities, regardless of indigeneity.
Indigenous groups in India were found to have excess mortality rates compared with non-indigenous groups. A socioeconomic gradient within indigenous populations was also found.
Editors' Summary
In many parts of the world the majority of the population are the descendants of immigrants who arrived there within the last few hundred years. Living alongside of them, and in a minority, are the so-called indigenous (or aboriginal) people who are the descendants of people who lived there in more ancient times. It is estimated that there are 300 million indigenous people worldwide. They are frequently marginalized from the rest of the population, their human rights are often abused, and there are serious concerns about their health and welfare. The state of health of the indigenous people of developed countries such as the US and Australia has often been studied, and we have a fairly clear idea of the kinds of problems these people face. Most indigenous people, however, live in developing countries, and less is known about their health.
India is the second-most populous country in the world, with an estimated 1.1 billion inhabitants. An estimated 90 million indigenous people live in India, where they are often referred to as “scheduled tribes” or Adivasis. They live in many parts of the country but are much more numerous in some Indian states than in others.
Why Was This Study Done?
It has often been said that indigenous people in India have worse health than other Indians, though no figures have been compiled to confirm these claims. The researchers wanted to establish whether it is simply an issue of indigenous people being poorer than other Indians—poverty being well known as a cause of disease—or whether being indigenous is, in itself, a health risk. The researchers also wanted to establish whether there are health inequalities within indigenous groups, and if these differences also followed a socioeconomic patterning.
What Did the Researchers Do and Find?
They used figures collected in the 1998–1999 Indian National Family Health Survey. When this survey was conducted, it was noted whether people were considered to be members of scheduled tribes. The researchers also knew, from the survey, about the income of the families, their death rates, and whether they drank alcohol or smoked or chewed tobacco. They found that indigenous people had higher death rates than other Indians. They made statistical calculations to account for differences in standard of living, and this substantially reduced the difference in death rate among indigenous groups, but an indigenous person was still 1.2 times more likely to die than a non-indigenous person with the same standard of living. Indigenous people were also more likely to drink alcohol and smoke tobacco, and here again, differences in standard of living accounted for a substantial portion of the differences. Importantly, the researchers' analysis showed a strong socioeconomic patterning of health inequalities within the indigenous population groups: the health differences between the poorest and richest indigenous groups were similar in scale to the differences between the poorest and richest non-indigenous groups.
What Do These Findings Mean?
The authors consider their finding that there is a socioeconomic gradient in mortality and health behaviors among indigenous people to be an important result from the study. The socioeconomic marginalization of indigenous people from the rest of Indian society does seem to increase their health risks, and so does their use of alcohol and tobacco. However, if their standard of living can be improved there would be major benefits for their health and welfare.
Additional Information.
Please access these Web sites via the online version of this summary at
A useful discussion of the term “indigenous people” (with links to documents about international agreements intended to improve their human rights) may be found on Wikipedia. (Wikipedia is an internet encyclopedia that anyone can edit.)
Survival International is a human rights organization that campaigns for the rights of indigenous peoples, helping them preserve their land and culture.
The charity Health Unlimited also works with indigenous people and its Web site includes links to recent studies and conferences.
A news item from the BBC describes a recent investigation into the health of indigenous people worldwide.
The World Health Organization has produced a number of reports on the health of indigenous people
PMCID: PMC1621109  PMID: 17076556
11.  Association of Lifecourse Socioeconomic Status with Chronic Inflammation and Type 2 Diabetes Risk: The Whitehall II Prospective Cohort Study 
PLoS Medicine  2013;10(7):e1001479.
Silvia Stringhini and colleagues followed a group of British civil servants over 18 years to look for links between socioeconomic status and health.
Please see later in the article for the Editors' Summary
Socioeconomic adversity in early life has been hypothesized to “program” a vulnerable phenotype with exaggerated inflammatory responses, so increasing the risk of developing type 2 diabetes in adulthood. The aim of this study is to test this hypothesis by assessing the extent to which the association between lifecourse socioeconomic status and type 2 diabetes incidence is explained by chronic inflammation.
Methods and Findings
We use data from the British Whitehall II study, a prospective occupational cohort of adults established in 1985. The inflammatory markers C-reactive protein and interleukin-6 were measured repeatedly and type 2 diabetes incidence (new cases) was monitored over an 18-year follow-up (from 1991–1993 until 2007–2009). Our analytical sample consisted of 6,387 non-diabetic participants (1,818 women), of whom 731 (207 women) developed type 2 diabetes over the follow-up. Cumulative exposure to low socioeconomic status from childhood to middle age was associated with an increased risk of developing type 2 diabetes in adulthood (hazard ratio [HR] = 1.96, 95% confidence interval: 1.48–2.58 for low cumulative lifecourse socioeconomic score and HR = 1.55, 95% confidence interval: 1.26–1.91 for low-low socioeconomic trajectory). 25% of the excess risk associated with cumulative socioeconomic adversity across the lifecourse and 32% of the excess risk associated with low-low socioeconomic trajectory was attributable to chronically elevated inflammation (95% confidence intervals 16%–58%).
In the present study, chronic inflammation explained a substantial part of the association between lifecourse socioeconomic disadvantage and type 2 diabetes. Further studies should be performed to confirm these findings in population-based samples, as the Whitehall II cohort is not representative of the general population, and to examine the extent to which social inequalities attributable to chronic inflammation are reversible.
Please see later in the article for the Editors' Summary
Editors' Summary
Worldwide, more than 350 million people have diabetes, a metabolic disorder characterized by high amounts of glucose (sugar) in the blood. Blood sugar levels are normally controlled by insulin, a hormone released by the pancreas after meals (digestion of food produces glucose). In people with type 2 diabetes (the commonest form of diabetes) blood sugar control fails because the fat and muscle cells that normally respond to insulin by removing sugar from the blood become insulin resistant. Type 2 diabetes, which was previously called adult-onset diabetes, can be controlled with diet and exercise, and with drugs that help the pancreas make more insulin or that make cells more sensitive to insulin. However, as the disease progresses, the pancreatic beta cells, which make insulin, become impaired and patients may eventually need insulin injections. Long-term complications, which include an increased risk of heart disease and stroke, reduce the life expectancy of people with diabetes by about 10 years compared to people without diabetes.
Why Was This Study Done?
Socioeconomic adversity in childhood seems to increase the risk of developing type 2 diabetes but why? One possibility is that chronic inflammation mediates the association between socioeconomic adversity and type 2 diabetes. Inflammation, which is the body's normal response to injury and disease, affects insulin signaling and increases beta-cell death, and markers of inflammation such as raised blood levels of C-reactive protein and interleukin 6 are associated with future diabetes risk. Notably, socioeconomic adversity in early life leads to exaggerated inflammatory responses later in life and people exposed to social adversity in adulthood show greater levels of inflammation than people with a higher socioeconomic status. In this prospective cohort study (an investigation that records the baseline characteristics of a group of people and then follows them to see who develops specific conditions), the researchers test the hypothesis that chronically increased inflammatory activity in individuals exposed to socioeconomic adversity over their lifetime may partly mediate the association between socioeconomic status over the lifecourse and future type 2 diabetes risk.
What Did the Researchers Do and Find?
To assess the extent to which chronic inflammation explains the association between lifecourse socioeconomic status and type 2 diabetes incidence (new cases), the researchers used data from the Whitehall II study, a prospective occupational cohort study initiated in 1985 to investigate the mechanisms underlying previously observed socioeconomic inequalities in disease. Whitehall II enrolled more than 10,000 London-based government employees ranging from clerical/support staff to administrative officials and monitored inflammatory marker levels and type 2 diabetes incidence in the study participants from 1991–1993 until 2007–2009. Of 6,387 participants who were not diabetic in 1991–1993, 731 developed diabetes during the 18-year follow-up. Compared to participants with the highest cumulative lifecourse socioeconomic score (calculated using information on father's occupational position and the participant's educational attainment and occupational position), participants with the lowest score had almost double the risk of developing diabetes during follow-up. Low lifetime socioeconomic status trajectories (being socially downwardly mobile or starting and ending with a low socioeconomic status) were also associated with an increased risk of developing diabetes in adulthood. A quarter of the excess risk associated with cumulative socioeconomic adversity and nearly a third of the excess risk associated with low socioeconomic trajectory was attributable to chronically increased inflammation.
What Do These Findings Mean?
These findings show a robust association between adverse socioeconomic circumstances over the lifecourse of the Whitehall II study participants and the risk of type 2 diabetes and suggest that chronic inflammation explains up to a third of this association. The accuracy of these findings may be affected by the measures of socioeconomic status used in the study. Moreover, because the study participants were from an occupational cohort, these findings need to be confirmed in a general population. Studies are also needed to examine the extent to which social inequalities in diabetes risk that are attributable to chronic inflammation are reversible. Importantly, if future studies confirm and extend the findings reported here, it might be possible to reduce the social inequalities in type 2 diabetes by promoting interventions designed to reduce inflammation, including weight management, physical activity, and smoking cessation programs and the use of anti-inflammatory drugs, among socially disadvantaged groups.
Additional Information
Please access these Web sites via the online version of this summary at
The US National Diabetes Information Clearinghouse provides information about diabetes for patients, health-care professionals, and the general public, including information on diabetes prevention (in English and Spanish)
The UK National Health Service Choices website provides information for patients and carers about type 2 diabetes; it includes peoples stories about diabetes
The nonprofit Diabetes UK also provides detailed information about diabetes for patients and carers, including information on healthy lifestyles for people with diabetes, and has a further selection of stories from people with diabetes; the nonprofit Healthtalkonline has interviews with people about their experiences of diabetes
MedlinePlus provides links to further resources and advice about diabetes (in English and Spanish)
Information about the Whitehall II study is available
PMCID: PMC3699448  PMID: 23843750
12.  Socioeconomic Inequalities in Lung Cancer Treatment: Systematic Review and Meta-Analysis 
PLoS Medicine  2013;10(2):e1001376.
In a systematic review and meta-analysis, Lynne Forrest and colleagues find that patients with lung cancer who are more socioeconomically deprived are less likely to receive surgical treatment, chemotherapy, or any type of treatment combined, compared with patients who are more socioeconomically well off, regardless of cancer stage or type of health care system.
Intervention-generated inequalities are unintended variations in outcome that result from the organisation and delivery of health interventions. Socioeconomic inequalities in treatment may occur for some common cancers. Although the incidence and outcome of lung cancer varies with socioeconomic position (SEP), it is not known whether socioeconomic inequalities in treatment occur and how these might affect mortality. We conducted a systematic review and meta-analysis of existing research on socioeconomic inequalities in receipt of treatment for lung cancer.
Methods and Findings
MEDLINE, EMBASE, and Scopus were searched up to September 2012 for cohort studies of participants with a primary diagnosis of lung cancer (ICD10 C33 or C34), where the outcome was receipt of treatment (rates or odds of receiving treatment) and where the outcome was reported by a measure of SEP. Forty-six papers met the inclusion criteria, and 23 of these papers were included in meta-analysis. Socioeconomic inequalities in receipt of lung cancer treatment were observed. Lower SEP was associated with a reduced likelihood of receiving any treatment (odds ratio [OR] = 0.79 [95% CI 0.73 to 0.86], p<0.001), surgery (OR = 0.68 [CI 0.63 to 0.75], p<0.001) and chemotherapy (OR = 0.82 [95% CI 0.72 to 0.93], p = 0.003), but not radiotherapy (OR = 0.99 [95% CI 0.86 to 1.14], p = 0.89), for lung cancer. The association remained when stage was taken into account for receipt of surgery, and was found in both universal and non-universal health care systems.
Patients with lung cancer living in more socioeconomically deprived circumstances are less likely to receive any type of treatment, surgery, and chemotherapy. These inequalities cannot be accounted for by socioeconomic differences in stage at presentation or by differences in health care system. Further investigation is required to determine the patient, tumour, clinician, and system factors that may contribute to socioeconomic inequalities in receipt of lung cancer treatment.
Please see later in the article for the Editors' Summary
Editors' Summary
Lung cancer is the most commonly occurring cancer worldwide and the commonest cause of cancer-related death. Like all cancers, lung cancer occurs when cells begin to grow uncontrollably because of changes in their genes. The most common trigger for these changes in lung cancer is exposure to cigarette smoke. Most cases of lung cancer are non-small cell lung cancer, the treatment for which depends on the “stage” of the disease when it is detected. Stage I tumors, which are confined to the lung, can be removed surgically. Stage II tumors, which have spread to nearby lymph nodes, are usually treated with surgery plus chemotherapy or radiotherapy. For more advanced tumors, which have spread throughout the chest (stage III) or throughout the body (stage IV), surgery generally does not help to slow tumor growth and the cancer is treated with chemotherapy and radiotherapy. Small cell lung cancer, the other main type of lung cancer, is nearly always treated with chemotherapy and radiotherapy but sometimes with surgery as well. Overall, because most lung cancers are not detected until they are quite advanced, less than 10% of people diagnosed with lung cancer survive for 5 years.
Why Was This Study Done?
As with many other cancers, socioeconomic inequalities have been reported for both the incidence of and the survival from lung cancer in several countries. It is thought that the incidence of lung cancer is higher among people of lower socioeconomic position than among wealthier people, in part because smoking rates are higher in poorer populations. Similarly, it has been suggested that survival is worse among poorer people because they tend to present with more advanced disease, which has a worse prognosis (predicted outcome) than early disease. But do socioeconomic inequalities in treatment exist for lung cancer and, if they do, could these inequalities contribute to the poor survival rates among populations of lower socioeconomic position? In this systematic review and meta-analysis, the researchers investigate the first of these questions. A systematic review uses predefined criteria to identify all the research on a given topic; a meta-analysis is a statistical approach that combines the results of several studies.
What Did the Researchers Do and Find?
The researchers identified 46 published papers that studied people with lung cancer in whom receipt of treatment was reported in terms of an indicator of socioeconomic position, such as a measure of income or deprivation. Twenty-three of these papers were suitable for inclusion in a meta-analysis. Lower socioeconomic position was associated with a reduced likelihood of receiving any treatment. Specifically, the odds ratio (chance) of people in the lowest socioeconomic group receiving any treatment was 0.79 compared to people in the highest socioeconomic group. Lower socioeconomic position was also associated with a reduced chance of receiving surgery (OR = 0.68) and chemotherapy (OR = 0.82), but not radiotherapy. The association between socioeconomic position and surgery remained after taking cancer stage into account. That is, when receipt of surgery was examined in early-stage patients only, low socioeconomic position remained associated with reduced likelihood of surgery. Notably, the association between socioeconomic position and receipt of treatment was similar in studies undertaken in countries where health care is free at the point of service for everyone (for example, the UK) and in countries with primarily private insurance health care systems (for example, the US).
What Do These Findings Mean?
These findings suggest that patients in more socioeconomically deprived circumstances are less likely to receive any type of treatment, surgery, and chemotherapy (but not radiotherapy) for lung cancer than people who are less socioeconomically deprived. Importantly, these inequalities cannot be explained by socioeconomic differences in stage at presentation or by differences in health care system. The accuracy of these findings may be affected by several factors. For example, it is possible that only studies that found an association between socioeconomic position and receipt of treatment have been published (publication bias). Moreover, the studies identified did not include information regarding patient preferences, which could help explain at least some of the differences. Nevertheless, these results do suggest that socioeconomic inequalities in receipt of treatment may exacerbate socioeconomic inequalities in the incidence of lung cancer and may contribute to the observed poorer outcomes in lower socioeconomic position groups. Further research is needed to determine the system and patient factors that contribute to socioeconomic inequalities in lung cancer treatment before clear recommendations for changes to policy and practice can be made.
Additional Information
Please access these Web sites via the online version of this summary at
The US National Cancer Institute provides information about all aspects of lung cancer for patients and health care professionals (in English and Spanish); a monograph entitled Area Socioeconomic Variations in U. S. Cancer Incidence, Mortality, Stage, Treatment, and Survival, 19751999 is available
Cancer Research UK also provides detailed information about lung cancer and links to other resources, such as a policy statement on socioeconomic inequalities in cancer and a monograph detailing cancer and health inequalities in the UK
The UK National Health Service Choices website has a page on lung cancer that includes personal stories about diagnosis and treatment
MedlinePlus provides links to other US sources of information about lung cancer (in English and Spanish)
PMCID: PMC3564770  PMID: 23393428
13.  The Fall and Rise of US Inequities in Premature Mortality: 1960–2002 
PLoS Medicine  2008;5(2):e46.
Debates exist as to whether, as overall population health improves, the absolute and relative magnitude of income- and race/ethnicity-related health disparities necessarily increase—or derease. We accordingly decided to test the hypothesis that health inequities widen—or shrink—in a context of declining mortality rates, by examining annual US mortality data over a 42 year period.
Methods and Findings
Using US county mortality data from 1960–2002 and county median family income data from the 1960–2000 decennial censuses, we analyzed the rates of premature mortality (deaths among persons under age 65) and infant death (deaths among persons under age 1) by quintiles of county median family income weighted by county population size. Between 1960 and 2002, as US premature mortality and infant death rates declined in all county income quintiles, socioeconomic and racial/ethnic inequities in premature mortality and infant death (both relative and absolute) shrank between 1966 and 1980, especially for US populations of color; thereafter, the relative health inequities widened and the absolute differences barely changed in magnitude. Had all persons experienced the same yearly age-specific premature mortality rates as the white population living in the highest income quintile, between 1960 and 2002, 14% of the white premature deaths and 30% of the premature deaths among populations of color would not have occurred.
The observed trends refute arguments that health inequities inevitably widen—or shrink—as population health improves. Instead, the magnitude of health inequalities can fall or rise; it is our job to understand why.
Nancy Krieger and colleagues found evidence of decreasing, and then increasing or stagnating, socioeconomic and racial inequities in US premature mortality and infant death from 1960 to 2002.
Editors' Summary
One of the biggest aims of public health advocates and governments is to improve the health of the population. Improving health increases people's quality of life and helps the population be more economically productive. But within populations are often persistent differences (usually called “disparities” or “inequities”) in the health of different subgroups—between women and men, different income groups, and people of different races/ethnicities, for example. Researchers study these differences so that policy makers and the broader public can be informed about what to do to intervene. For example, if we know that the health of certain subgroups of the population—such as the poor—is staying the same or even worsening as the overall health of the population is improving, policy makers could design programs and devote resources to specifically target the poor.
To study health disparities, researchers use both relative and absolute measures. Relative inequities refer to ratios, while absolute inequities refer to differences. For example, if one group's average income level increases from $1,000 to $10,000 and another group's from $2,000 to $20,000, the relative inequality between the groups stays the same (i.e., the ratio of incomes between the two groups is still 2) but the absolute difference between the two groups has increased from $1,000 to $10,000.
Examining the US population, Nancy Krieger and colleagues looked at trends over time in both relative and absolute differences in mortality between people in different income groups and between whites and people of color.
Why Was This Study Done?
There has been a lot of debate about whether disparities have been widening or narrowing as overall population health improves. Some research has found that both total health and health disparities are getting better with time. Other research has shown that overall health gains mask worsening disparities—such that the rich get healthier while the poor get sicker.
Having access to more data over a longer time frame meant that Krieger and colleagues could provide a more complete picture of this sometimes contradictory story. It also meant they could test their hypothesis about whether, as population health improves, health inequities necessarily widen or shrink within the time period between the 1960s through the 1990s during which certain events and policies likely would have had an impact on the mortality trends in that country.
What Did the Researchers Do and Find?
In order to investigate health inequities, the authors chose to look at two common measures of population health: rates of premature mortality (dying before the age of 65 years) and rates of infant mortality (death before the age of 1).
To determine mortality rates, the authors used death statistics data from different counties, which are routinely collected by state and national governments. To be able to rank mortality rates for different income groups, they used data on the median family incomes of people living within those counties (meaning half the families had income above, and half had incomes below, the median value). They calculated mortality rates for the total population and for whites versus people of color. They used data from 1960 through 2002. They compared rates for 1966–1980 with two other time periods: 1960–1965 and 1981–2002. They also examined trends in the annual mortality rates and in the annual relative and absolute disparites in these rates by county income level.
Over the whole period 1960–2002, the authors found that premature mortality (death before the age of 65) and infant mortality (death before the age of 1) decreased for all income groups. But they also found that disparities between income groups and between whites and people of color were not the same over this time period. In fact, the economic disparities narrowed then widened. First, they shrank between 1966 and 1980, especially for Americans of color. After 1980, however, the relative health inequities widened and the absolute differences did not change. The authors conclude that if all people in the US population experienced the same health gains as the most advantaged did during these 42 years (i.e., as the whites in the highest income groups), 14% of the premature deaths among whites and 30% of the premature deaths among people of color would have been prevented.
What Do These Findings Mean?
The findings provide an overview of the trends in inequities in premature and infant mortality over a long period of time. Different explanations for these trends can now be tested. The authors discuss several potential reasons for these trends, including generally rising incomes across America and changes related to specific diseases, such as the advent of HIV/AIDS, changes in smoking habits, and better management of cancer and cardiovascular disease. But they find that these do not explain the fall then rise of inequities. Instead, the authors suggest that explanations lie in the social programs of the 1960s and the subsequent roll-back of some of these programmes in the 1980s. The US “War on Poverty,” civil rights legislation, and the establishment of Medicare occurred in the mid 1960s, which were intended to reduce socioeconomic and racial/ethnic inequalities and improve access to health care. In the 1980s there was a general cutting back of welfare state provisions in America, which included cuts to public health and antipoverty programs, tax relief for the wealthy, and worsening inequity in the access to and quality of health care. Together, these wider events could explain the fall then rise trends in mortality disparities.
The authors say their findings are important to inform and help monitor the progress of various policies and programmes, including those such as the Healthy People 2010 initiative in America, which aims to increase the quality and years of healthy life and decrease health disparities by the end of this decade.
Additional Information.
Please access these Web sites via the online version of this summary at 0050046.
Healthy People 2010 was created by the US Department of Health and Human Services along with scientists inside and outside of government and includes a comprehensive set of disease prevention and health promotion objectives for the US to achieve by 2010, with two overarching goals: to increase quality and years of healthy life and to eliminate health disparities
Johan Mackenbach and colleagues provide an overview of mortality inequalities in six Western European countries—Finland, Sweden, Norway, Denmark, England/Wales, and Italy—and conclude that eliminating mortality inequalities requires that more cardiovascular deaths among lower socioeconomic groups be prevented, as well as more attention be paid to rising death rates of lung cancer, breast cancer, respiratory disease, gastrointestinal disease, and injuries among women and men in the lower income groups.
The WHO Health for All program promotes health equity
A primer on absolute versus relative differences is provided by the American College of Physicians
PMCID: PMC2253609  PMID: 18303941
14.  Early socioeconomic position and self-rated health among civil servants in Brazil: a cross-sectional analysis from the Pró-Saúde cohort study 
BMJ Open  2014;4(11):e005321.
Although there is evidence that socioeconomic conditions in adulthood are associated with worse self-rated health, the putative effect of early adverse life circumstances on adult self-rated health is not consistent. Besides, little is known on this subject in the context of middle-income countries. We aimed to investigate the association between indicators of socioeconomic position in early life and self-rated health in adulthood, taking into account the influence of current socioeconomic position.
3339 civil servants (44.5% male) working at a public university in Rio de Janeiro, Brazil, participants of the Pró-Saúde cohort study.
Through a lifecourse approach, we evaluated if seven indicators of participants’ socioeconomic position earlier in life were associated with worse self-rated health in adulthood. Ordinal logistic regression analysis with a proportional odds model was used.
After adjusting for socioeconomic position in adulthood (education and income), the indicators of early socioeconomic position associated with poor self-rated health were as follows: not eating at home due to lack of money at the age of 12 (OR=1.29 95% CI 1.06 to 1.57) and having lived in a small city or rural area at the age of 12 (OR=1.51 95% CI 1.21 to 1.89).
Self-rated health was associated with two indicators of remarkable experiences of poverty in early life, even when socioeconomic conditions improved throughout life. Our findings have shown a long-term impact of extreme socioeconomic hardship during childhood and/or adolescence on the development of social inequalities in health. In terms of implications for public health, our work emphasises that health policies, usually focused on adult lifestyle interventions, should be complemented by initiatives aimed at reducing socioeconomic inequalities during the earliest stages of development, such as childhood and adolescence.
PMCID: PMC4244401  PMID: 25416056
15.  Relationships between Reward Sensitivity, Risk-Taking and Family History of Alcoholism during an Interactive Competitive fMRI Task 
PLoS ONE  2014;9(2):e88188.
Individuals with a positive family history for alcoholism (FHP) have shown differences from family-history-negative (FHN) individuals in the neural correlates of reward processing. FHP, compared to FHN individuals, demonstrate relatively diminished ventral striatal activation during anticipation of monetary rewards, and the degree of ventral striatal activation shows an inverse correlation with specific impulsivity measures in alcohol-dependent individuals. Rewards in socially interactive contexts relate importantly to addictive propensities, yet have not been examined with respect to how their neural underpinnings relate to impulsivity-related measures. Here we describe impulsivity measures in FHN and FHP individuals as they relate to a socially interactive functional magnetic resonance imaging (fMRI) task.
Forty FHP and 29 FHN subjects without histories of Axis-I disorders completed a socially interactive Domino task during functional magnetic resonance imaging and completed self-report and behavioral impulsivity-related assessments.
FHP compared to FHN individuals showed higher scores (p = .004) on one impulsivity-related factor relating to both compulsivity (Padua Inventory) and reward/punishment sensitivity (Sensitivity to Punishment/Sensitivity to Reward Questionnaire). Multiple regression analysis within a reward-related network revealed a correlation between risk-taking (involving another impulsivity-related factor, the Balloon Analog Risk Task (BART)) and right ventral striatum activation under reward >punishment contrast (p<0.05 FWE corrected) in the social task.
Behavioral risk-taking scores may be more closely associated with neural correlates of reward responsiveness in socially interactive contexts than are FH status or impulsivity-related self-report measures. These findings suggest that risk-taking assessments be examined further in socially interactive settings relevant to addictive behaviors.
PMCID: PMC3913753  PMID: 24505424
16.  Social inequalities in patient experiences with general practice and in access to specialists: the population-based HUNT Study 
In countries with gatekeeping and equitable access to general practitioners (GPs), social inequalities in GP-patient interaction could be an important mechanism by which inequalities in access to medical specialists arise. The aim of this study was to investigate whether socioeconomic inequalities in experiences with general practice are associated with socioeconomic inequalities in access to specialist services.
The study included 6,067 participants in the third survey of the Nord-Trøndelag Health Study (HUNT3, 2006–08) who were asked to evaluate their experiences with primary care and their regular general practitioner in Norway. Self-reported data on health status and number of visits to GP and specialist services in the last 12 months were included in the study. Socioeconomic status was measured by education and household income and rescaled to relative index of inequality (RII). Relative risks were calculated using Poisson regression.
We found that a majority of patients reported positive experiences with general practice. Low socioeconomic status (SES) and male gender were associated with negative experiences. Patient experiences both directly and indirectly related to referrals were associated with the probability and quantity of specialist utilization: perception of low subjective influence on decisions about choice of medical care was associated with lower probability and quantity of specialist utilization, whereas desire to change the regular GP or to use GPs other than the regular GP and critical evaluations of the GP were associated with higher specialist consultation frequency. However, the level of education-related inequity in access to specialists was not sensitive to adjustment by survey responses.
Patient experiences with general practice were associated with the patients’ level of utilization of specialist services. There are socioeconomic inequalities in patient experiences with general practice, however the aspects measured in this study do not explain the observed socioeconomic inequity in access to specialists.
PMCID: PMC3718649  PMID: 23816237
Social inequalities; Socioeconomic; Health services research; Health care utilization; General practice; Patient experiences; Norway
17.  Poverty, social exclusion and dental caries of 12-year-old children: a cross-sectional study in Lima, Peru 
BMC Oral Health  2009;9:16.
Socioeconomic differences in oral health have been reported in many countries. Poverty and social exclusion are two commonly used indicators of socioeconomic position in Latin America. The aim of this study was to explore the associations of poverty and social exclusion with dental caries experience in 12-year-old children.
Ninety families, with a child aged 12 years, were selected from 11 underserved communities in Lima (Peru), using a two-stage cluster sampling. Head of households were interviewed with regard to indicators of poverty and social exclusion and their children were clinically examined for dental caries. The associations of poverty and social exclusion with dental caries prevalence were tested in binary logistic regression models.
Among children in the sample, 84.5% lived in poor households and 30.0% in socially excluded families. Out of all the children, 83.3% had dental caries. Poverty and social exclusion were significantly associated with dental caries in the unadjusted models (p = 0.013 and 0.047 respectively). In the adjusted model, poverty remained significantly related to dental caries (p = 0.008), but the association between social exclusion and dental caries was no longer significant (p = 0.077). Children living in poor households were 2.25 times more likely to have dental caries (95% confidence interval: 1.24; 4.09), compared to those living in non-poor households.
There was support for an association between poverty and dental caries, but not for an association between social exclusion and dental caries in these children. Some potential explanations for these findings are discussed.
PMCID: PMC2713218  PMID: 19583867
18.  The Role of the Anterior Cingulate Cortex in Women’s Sexual Decision Making 
Neuroscience letters  2008;449(1):42-47.
Women’s sexual decision making is a complex process balancing the potential rewards of conception and pleasure against the risks of possible low paternal care or sexually transmitted infection. Although neural processes underlying social decision making are suggested to overlap with those involved in economic decision making, the neural systems associated with women’s sexual decision making are unknown. Using fMRI, we measured the brain activation of 12 women while they viewed photos of men’s faces. Face stimuli were accompanied by information regarding each man’s potential risk as a sexual partner, indicated by a written description of the man’s number of previous sexual partners and frequency of condom use. Participants were asked to evaluate how likely they would be to have sex with the man depicted. Women reported that they would be more likely to have sex with low compared to high risk men. Stimuli depicting low risk men also elicited stronger activation in the anterior cingulate cortex (ACC), midbrain, and intraparietal sulcus, possibly reflecting an influence of sexual risk on women’s attraction, arousal, and attention during their sexual decision making. Activation in the ACC was positively correlated with women’s subjective evaluations of sex likelihood and response times during their evaluations of high, but not low, risk men. These findings provide evidence that neural systems involved in sexual decision making in women overlap with those described previously to underlie nonsexual decision making.
PMCID: PMC2614659  PMID: 18992789
mate choice; decision making; anterior cingulated; risk
19.  Hyperoxic Brain Effects Are Normalized by Addition of CO2 
PLoS Medicine  2007;4(5):e173.
Hyperoxic ventilation (>21% O2) is widely used in medical practice for resuscitation, stroke intervention, and chronic supplementation. However, despite the objective of improving tissue oxygen delivery, hyperoxic ventilation can accentuate ischemia and impair that outcome. Hyperoxia results in, paradoxically, increased ventilation, which leads to hypocapnia, diminishing cerebral blood flow and hindering oxygen delivery. Hyperoxic delivery induces other systemic changes, including increased plasma insulin and glucagon levels and reduced myocardial contractility and relaxation, which may derive partially from neurally mediated hormonal and sympathetic outflow. Several cortical, limbic, and cerebellar brain areas regulate these autonomic processes. The aim of this study was to assess recruitment of these regions in response to hyperoxia and to determine whether any response would be countered by addition of CO2 to the hyperoxic gas mixture.
Methods and Findings
We studied 14 children (mean age 11 y, range 8–15 y). We found, using functional magnetic resonance imaging, that 2 min of hyperoxic ventilation (100% O2) following a room air baseline elicited pronounced responses in autonomic and hormonal control areas, including the hypothalamus, insula, and hippocampus, throughout the challenge. The addition of 5% CO2 to 95% O2 abolished responses in the hypothalamus and lingual gyrus, substantially reduced insular, hippocampal, thalamic, and cerebellar patterns in the first 48 s, and abolished signals in those sites thereafter. Only the dorsal midbrain responded to hypercapnia, but not hyperoxia.
In this group of children, hyperoxic ventilation led to responses in brain areas that modify hypothalamus-mediated sympathetic and hormonal outflow; these responses were diminished by addition of CO2 to the gas mixture. This study in healthy children suggests that supplementing hyperoxic administration with CO2 may mitigate central and peripheral consequences of hyperoxia.
Hyperoxic ventilation leads to responses in brain areas that modify hypothalamus-mediated sympathetic and hormonal outflow; these responses can be diminished by addition of CO2 to the gas mixture.
Editors' Summary
All cells in the human body need oxygen (O2) to keep them alive. O2 is absorbed into the blood from the air by the lungs (which also release carbon dioxide [CO2], a waste product of cells, from the blood into the air). The blood then delivers O2 to the rest of the body. For healthy people, breathing air (which contains 21% O2) is sufficient to keep their tissues healthy. But there are medical situations in which O2 delivery to tissues needs improving. For example, during resuscitation or after a stroke when the O2 supply to a part of the brain is disrupted. Premature babies often need help with O2 delivery because their immature lungs don't absorb O2 efficiently. In situations like these, the O2 supply can be increased by providing an O2-rich gas mixture to the lungs—so-called “hyperoxic (i.e., high O2) ventilation.” But, paradoxically, hyperoxic ventilation can make matters worse. Hyperoxia increases the exchange of air between the lungs and the atmosphere (hyperventilation), which reduces the CO2 level in the blood. This “hypocapnia,” i.e. low CO2, reduces the blood flow to the brain by narrowing the blood vessels. Hyperoxia also alters the heart rate and blood pressure and the blood levels of some hormones. It probably causes these changes by affecting the brain regions that control autonomic functions (body functions such as heart rate, insulin and other hormone release, sweating and gland action that are not controlled by conscious thought). All told, although hyperoxic ventilation saves lives, it can also have serious adverse effects. In premature babies, for example, although it is often essential for their survival, hyperoxic ventilation can cause serious heart muscle and brain injury or lung problems (bronchopulmonary dysplasia) if it is not carefully monitored.
Why Was This Study Done?
The addition of a little CO2 to the hyperoxic gas mix can reduce the adverse effects of hyperoxic ventilation on blood flow to the brain. However, it is unclear whether this alteration can also modify responses of brain areas that control autonomic functions and hormone release to hyperoxia. If it does, then CO2 supplementation could prevent those adverse effects of hyperoxic ventilation that affect the whole body. In this study, the researchers investigated whether hyperoxic ventilation increases neural responses in brain regions that regulate the activity of the hypothalamus (the part of the brain that controls autonomic bodily functions) and whether the addition of CO2 reduces these responses.
What Did the Researchers Do and Find?
The researchers used a technique called functional magnetic resonance imaging (fMRI) to measure the activity of different brain regions in 14 healthy young people (aged 8–15 years). Active regions of the brain draw more O2 out of the blood than inactive regions, and fMRI measures changes in blood O2 levels. fMRI images were obtained for all the study participants when they were breathing normal air and during two-minute challenges with 100% O2 or a 95% O2, 5% CO2 mix. Hyperoxic ventilation produced rapid and marked changes in the activity of brain areas involved in autonomic and hormonal control, including the hypothalamus and regions that control the hypothalamus. After the challenge with 95% O2, 5% CO2, these responses were either absent or greatly reduced in the brain regions that had responded to 100% O2.
What Do These Findings Mean?
These findings show that hyperoxic ventilation induces brain activity changes that are likely to affect autonomic functions and hormone release throughout the body. In addition, they show that the addition of CO2 to the gas mixture greatly diminishes these responses. Because the autonomic and hormonal changes induced by 100% O2 can potentially injure organs throughout the body, the addition of CO2 to hyperoxic gas mixtures could reduce many of the adverse effects of hyperoxic ventilation. These results, therefore, could influence how hyperoxic ventilation is used in medical practice. However, CO2 supplementation still needs to be tested in adults and newborn babies. Although the results presented here will probably hold true for adults, and both neonatal and developmental animal studies suggest that hyperoxia results in serious side effects in newborns over room air or hyperoxia with added CO2, the brain findings need to studied in babies, the portion of the population most likely to be treated with hyperoxic ventilation.
Additional Information.
Please access these Web sites via the online version of this summary at
The American Lung Association has patient information on the lungs and lung diseases, including bronchopulmonary dysplasia (in English and Spanish)
The Medlineplus encyclopedia contains pages on hyperventilation and on premature babies, and links to other information on premature babies (in English and Spanish)
Wikipedia has pages on the lungs, oxygen toxicity, mechanical ventilation, and hypocapnia (note that Wikipedia is a free online encyclopedia that anyone can edit; available in several languages)
PMCID: PMC1872042  PMID: 17518514
20.  Us versus Them: Social Identity Shapes Neural Responses to Intergroup Competition and Harm 
Psychological science  2011;22(3):10.1177/0956797610397667.
Intergroup competition makes social identity salient, which affects how people respond to competitors’ hardships. The failures of a fellow group member are painful, while those of a rival group member may give pleasure—a feeling that may motivate harming rivals. The present study examines whether valuation-related neural responses to rival groups’ failures correlate with likelihood of harming individuals associated with those rivals. Avid fans of the Red Sox and Yankees teams viewed baseball plays while undergoing fMRI. Subjectively negative outcomes (favored-failure, rival-success) activated anterior cingulate cortex and insula, while positive outcomes (favored-success, rival-failure—even against a third team) activated ventral striatum. The ventral striatum effect, associated with subjective pleasure, also correlated with self-reported likelihood of aggressing against a fan of the rival team (controlling for general aggression). Outcomes of social group competition can directly affect primary reward-processing neural systems, with implications for intergroup harm.
PMCID: PMC3833634  PMID: 21270447
21.  Food Insecurity and Mental Disorders in a National Sample of U.S. Adolescents 
To examine whether food insecurity is associated with past-year DSM-IV mental disorders after controlling for standard indicators of family socioeconomic status (SES) in a U.S. national sample of adolescents.
Data were drawn from 6,483 adolescent–parent pairs who participated in the National Comorbidity Survey Replication Adolescent Supplement, a national survey of adolescents 13 to 17 years old. Frequency and severity of food insecurity were assessed with questions based on the U.S. Department of Agriculture’s Food Security Scale (standardized to a mean of 0, variance of 1). DSM-IV mental disorders were assessed with the World Health Organization Composite International Diagnostic Interview. Associations of food insecurity with DSM-IV/Composite International Diagnostic Interview diagnoses were estimated with logistic regression models controlling for family SES (parental education, household income, relative deprivation, community-level inequality, and subjective social status).
Food insecurity was highest in adolescents with the lowest SES. Controlling simultaneously for other aspects of SES, standardized food insecurity was associated with an increased odds of past-year mood, anxiety, behavior, and substance disorders. A 1 standard deviation increase in food insecurity was associated with a 14%increase in the odds of past-year mental disorder, even after controlling for extreme poverty. The association between food insecurity and mood disorders was strongest in adolescents living in families with a low household income and high relative deprivation.
Food insecurity is associated with a wide range of adolescent mental disorders independently of other aspects of SES. Expansion of social programs aimed at decreasing family economic strain might be one useful policy approach for improving youth mental health.
PMCID: PMC3632292  PMID: 23200286
food insecurity; poverty; hunger; adolescence; mental health
22.  Diminished Neural Processing of Aversive and Rewarding Stimuli During Selective Serotonin Reuptake Inhibitor Treatment 
Biological Psychiatry  2010;67(5):439-445.
Selective serotonin reuptake inhibitors (SSRIs) are popular medications for anxiety and depression, but their effectiveness, particularly in patients with prominent symptoms of loss of motivation and pleasure, has been questioned. There are few studies of the effect of SSRIs on neural reward mechanisms in humans.
We studied 45 healthy participants who were randomly allocated to receive the SSRI citalopram, the noradrenaline reuptake inhibitor reboxetine, or placebo for 7 days in a double-blind, parallel group design. We used functional magnetic resonance imaging to measure the neural response to rewarding (sight and/or flavor of chocolate) and aversive stimuli (sight of moldy strawberries and/or an unpleasant strawberry taste) on the final day of drug treatment.
Citalopram reduced activation to the chocolate stimuli in the ventral striatum and the ventral medial/orbitofrontal cortex. In contrast, reboxetine did not suppress ventral striatal activity and in fact increased neural responses within medial orbitofrontal cortex to reward. Citalopram also decreased neural responses to the aversive stimuli conditions in key “punishment” areas such as the lateral orbitofrontal cortex. Reboxetine produced a similar, although weaker effect.
Our findings are the first to show that treatment with SSRIs can diminish the neural processing of both rewarding and aversive stimuli. The ability of SSRIs to decrease neural responses to reward might underlie the questioned efficacy of SSRIs in depressive conditions characterized by decreased motivation and anhedonia and could also account for the experience of emotional blunting described by some patients during SSRI treatment.
PMCID: PMC2828549  PMID: 20034615
Antidepressants; depression; fMRI; reward; SSRI; ventral striatum
23.  Remaining life expectancy among older people in a rural area of Vietnam: trends and socioeconomic inequalities during a period of multiple transitions 
BMC Public Health  2009;9:471.
Better understanding of the trends and disparities in health at old age in terms of life expectancy will help to provide appropriate responses to the growing needs of health and social care for the older population in the context of limited resources. As a result of rapid economic, demographic and epidemiological changes, the number of people aged 60 and over in Vietnam is increasing rapidly, from 6.7% in 1979 to 9.2% in 2006. Life expectancy at birth has increased but not much are known about changes in old ages. This study assesses the trends and socioeconomic inequalities in RLE at age 60 in a rural area in an effort to highlight this vulnerable group and to anticipate their future health and social needs.
An abridged life table adjusted for small area data was used to estimate cohort life expectancies at old age and the corresponding 95% confidence intervals from longitudinal data collected by FilaBavi DSS during 1999-2006, which covered 7,668 people at age 60+ with 43,272 person-years, out of a total of 64,053 people with 388,278 person-years. Differences in life expectancy were examined according to socioeconomic factors, including socio-demographic characteristics, wealth, poverty and living arrangements.
Life expectancies at age 60 have increased by approximately one year from the period 1999-2002 to 2003-2006. The increases are observed in both sexes, but are significant among females and relate to improvements among those who belong to the middle and upper household wealth quintiles. However, life expectancy tends to decrease in the most vulnerable groups. There is a wide gap in life expectancy according to poverty status and living arrangements, and the gap by poverty status has widened over the study period. The gender gap in life expectancy is consistent across all socioeconomic groups and tends to be wider amongst the more disadvantaged population.
There is a trend of increasing life expectancy among older people in rural areas of Vietnam. Inequalities in life expectancy exist between socioeconomic groups, especially between different poverty levels and also patterns of living arrangements. These inequalities should be addressed by appropriate social and health policies with stronger targeting of the poorest and most disadvantaged groups.
PMCID: PMC2803493  PMID: 20017933
24.  Neural representation of reward in recovered depressed patients 
Psychopharmacology  2009;205(4):667-677.
Anhedonia, a loss of interest and pleasure in normally rewarding stimuli, is a key diagnostic criterion for major depression. It has been suggested that deficits in the processing of reward-relevant stimuli could represent an endophenotype for depression. We hypothesized that people at risk of depression by virtue of a personal history of the illness would show impaired neural responses to a primary rewarding stimulus.
Materials and methods
Using functional magnetic resonance imaging, we measured the neural response to the sight and flavor of chocolate, and their combination, in 13 unmedicated recovered patients with a history of major depression and 14 healthy controls matched for age and gender. We also examined a control aversive condition consisting of the sight of moldy strawberries and a corresponding unpleasant taste. Participants simultaneously recorded subjective ratings of “pleasantness,” “intensity,” and “wanting.”
Results and discussion
Despite no differences between the groups in stimulus ratings, patients showed decreased neural responses to the pleasant stimulus in the ventral striatum and increases in the caudate nucleus to the aversive stimulus. Furthermore, patients had a diminished neural supralinearity response (the potentiation produced by simultaneous presentation of the sight and flavor of the stimuli) in the prefrontal cortex for both aversive and pleasant conditions. Patients recovered from depression appear to have deficits in the neural basis of reward and may also have impairments in the cross-modal integration of sensory stimuli.
These findings support the view that abnormal neural responses to reward may be an endophenotype for depression and a potential target for intervention and prevention strategies.
PMCID: PMC2718193  PMID: 19529923
fMRI; Depression; Reward; Chocolate; Endophenotype
25.  Family Poverty Affects the Rate of Human Infant Brain Growth 
PLoS ONE  2013;8(12):e80954.
Living in poverty places children at very high risk for problems across a variety of domains, including schooling, behavioral regulation, and health. Aspects of cognitive functioning, such as information processing, may underlie these kinds of problems. How might poverty affect the brain functions underlying these cognitive processes? Here, we address this question by observing and analyzing repeated measures of brain development of young children between five months and four years of age from economically diverse backgrounds (n = 77). In doing so, we have the opportunity to observe changes in brain growth as children begin to experience the effects of poverty. These children underwent MRI scanning, with subjects completing between 1 and 7 scans longitudinally. Two hundred and three MRI scans were divided into different tissue types using a novel image processing algorithm specifically designed to analyze brain data from young infants. Total gray, white, and cerebral (summation of total gray and white matter) volumes were examined along with volumes of the frontal, parietal, temporal, and occipital lobes. Infants from low-income families had lower volumes of gray matter, tissue critical for processing of information and execution of actions. These differences were found for both the frontal and parietal lobes. No differences were detected in white matter, temporal lobe volumes, or occipital lobe volumes. In addition, differences in brain growth were found to vary with socioeconomic status (SES), with children from lower-income households having slower trajectories of growth during infancy and early childhood. Volumetric differences were associated with the emergence of disruptive behavioral problems.
PMCID: PMC3859472  PMID: 24349025

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