Search tips
Search criteria

Results 1-25 (1156426)

Clipboard (0)

Related Articles

1.  Are caregiving responsibilities associated with non-attendance at breast screening? 
BMC Public Health  2010;10:749.
Previous research showed that deprived individuals are less likely to attend breast screening and those providing intense amounts of informal care tend to be more deprived than non-caregivers. The aim of this study was to examine the relationship between informal caregiving and uptake of breast screening and to determine if socio-economic gradients in screening attendance were explained by caregiving responsibilities.
A database of breast screening histories was linked to the Northern Ireland Longitudinal Study, which links information from census, vital events and health registration datasets. The cohort included women aged 47 - 64 at the time of the census eligible for breast screening in a three-year follow-up period. Cohort attributes were recorded at the Census. Multivariate logistic regression was used to examine the relationship between informal caregiving and uptake of screening using STATA version 10.
37,211 women were invited for breast screening of whom 27,909 (75%) attended; 23.9% of the cohort were caregivers. Caregivers providing <20 hours of care/week were more affluent, while those providing >50 hours/week were more deprived than non-caregivers. Deprived women were significantly less likely to attend breast screening; however, this was not explained by caregiving responsibilities as caregivers were as likely as non-caregivers to attend (Odds Ratio 0.97; 95% confidence intervals 0.88, 1.06).
While those providing the most significant amounts of care tended to be more deprived, caregiving responsibilities themselves did not explain the known socio-economic gradients in breast screening attendance. More work is required to identify why more deprived women are less likely to attend breast screening.
PMCID: PMC3003649  PMID: 21129196
2.  Major ethnic group differences in breast cancer screening uptake in Scotland are not extinguished by adjustment for indices of geographical residence, area deprivation, long-term illness and education 
British Journal of Cancer  2012;106(8):1361-1366.
Breast cancer screening data generally show lower uptake in minority ethnic groups. We investigated whether such variations occur in Scotland.
Using non-disclosive computerised linkage we combined Scottish breast screening and Census 2001 data. Non-attendance at first breast-screening invitation (2002–2008) was compared between 11 ethnic groups using age-adjusted risk ratios (RR) with 95% confidence intervals (CI), multiplied by 100, using Poisson regression.
Compared with the White Scottish (RR=100), non-attendance was similar for Other White British (99.5, 95% CI 96.1–103.2) and Chinese (112.8, 95% CI 96.3–132.2) and higher for Pakistani (181.7, 95% CI 164.9–200.2), African (162.2, 95% CI 130.8–201.1), Other South Asian (151.7, 95% CI 118.9–193.7) and Indian (141.7, 95% CI 121.1–165.7) groups. Adjustment for rural vs urban residence, long-term illness, area deprivation and education, associated with risk of non-attendance, increased the RR for non-attendance except for Pakistani women where it was modestly attenuated (RR=164.9, 149.4–182.1).
Our data show important inequality in breast cancer screening uptake, not attenuated by potential confounding factors. Ethnic inequalities in breast screening attendance are of concern especially given evidence that the traditionally lower breast cancer rates in South Asian groups are converging towards the risks in the White UK population. Notwithstanding the forthcoming review of breast cancer screening, these data call for urgent action.
PMCID: PMC3326672  PMID: 22415231
breast cancer; cancer screening; ethnicity; inequalities
3.  Comparison of breast and bowel cancer screening uptake patterns in a common cohort of South Asian women in England 
Inequalities in uptake of cancer screening by ethnic minority populations are well documented in a number of international studies. However, most studies to date have explored screening uptake for a single cancer only. This paper compares breast and bowel cancer screening uptake for a cohort of South Asian women invited to undertake both, and similarly investigates these women's breast cancer screening behaviour over a period of fifteen years.
Screening data for rounds 1, 2 and 5 (1989-2004) of the NHS breast cancer screening programme and for round 1 of the NHS bowel screening pilot (2000-2002) were obtained for women aged 50-69 resident in the English bowel screening pilot site, Coventry and Warwickshire, who had been invited to undertake breast and bowel cancer screening in the period 2000-2002. Breast and bowel cancer screening uptake levels were calculated and compared using the chi-squared test.
72,566 women were invited to breast and bowel cancer screening after exclusions. Of these, 3,539 were South Asian and 69,027 non-Asian; 18,730 had been invited to mammography over the previous fifteen years (rounds 1 to 5). South Asian women were significantly less likely to undertake both breast and bowel cancer screening; 29.9% (n = 1,057) compared to 59.4% (n = 40,969) for non-Asians (p < 0.001). Women in both groups who consistently chose to undertake breast cancer screening in rounds 1, 2 and 5 were more likely to complete round 1 bowel cancer screening. However, the likelihood of completion of bowel cancer screening was still significantly lower for South Asians; 49.5% vs. 82.3% for non-Asians, p < 0.001. South Asian women who undertook breast cancer screening in only one round were no more likely to complete bowel cancer screening than those who decided against breast cancer screening in all three rounds. In contrast, similar women in the non-Asian population had an increased likelihood of completing the new bowel cancer screening test. The likelihood of continued uptake of mammography after undertaking screening in round 1 differed between South Asian religio-linguistic groups. Noticeably, women in the Muslim population were less likely to continue to participate in mammography than those in other South Asian groups.
Culturally appropriate targeted interventions are required to reduce observed disparities in cancer screening uptakes.
PMCID: PMC2867962  PMID: 20423467
4.  Identifying Risk Factors for Disparities in Breast Cancer Mortality among African-American and Hispanic Women 
This study evaluated the risk factors associated with racial disparities in female breast cancer mortality for African-American and Hispanic women at the census tract level in Texas from 1995 to 2005.
Data on female breast cancer cases were obtained from the Texas Cancer Registry. Socioeconomic and demographic data were collected from Census 2000. Network distance and driving times to mammography facilities were estimated using Geographic Information System techniques. Demographic, poverty and spatial accessibility factors were constructed using principal component analysis. Logistic regression models were developed to predict the census tracts with significant racial disparities in breast cancer mortality based on racial disparities in late-stage diagnosis and structured factors from the principal component analysis.
Late-stage diagnosis, poverty factors, and demographic factors were found to be significant predictors of a census tract showing significant racial disparities in breast cancer mortality. Census tracts with higher poverty status were more likely to display significant racial disparities in breast cancer mortality for both African Americans (odds ratio [OR], 2.43; 95% confidence interval [CI], 1.95–3.04) and Hispanics (OR, 5.30; 95% CI, 4.26–6.59). Spatial accessibility was not a consistent predictor of racial disparities in breast cancer mortality for African-American and Hispanic women.
Physical access to mammography facilities does not necessarily reflect a greater utilization of mammogram screening, possibly owing to financial constraints. Therefore, a metric measuring access to health care facilities is needed to capture all aspects of access to preventive care. Despite easier physical access to mammography facilities in metropolitan areas, great resources and efforts should also be devoted to these areas where racial disparities in breast cancer mortality are often found.
PMCID: PMC4338013  PMID: 22265181
5.  Educational inequalities in mortality and associated risk factors: German- versus French-speaking Switzerland 
BMC Public Health  2010;10:567.
Between the French- and German-speaking areas of Switzerland, there are distinct differences in mortality, similar to those between Germany and France. Assessing corresponding inequalities may elucidate variations in mortality and risk factors, thereby uncovering public health potential. Our aim was to analyze educational inequalities in all-cause and cause-specific mortality in the two Swiss regions and to compare this with inequalities in behavioural risk factors and self-rated health.
The Swiss National Cohort, a longitudinal census-based record linkage study, provided mortality and survival time data (3.5 million individuals, 40-79 years, 261,314 deaths, 1990-2000). The Swiss Health Survey 1992/93 provided cross-sectional data on risk factors. Inequalities were calculated as percentage of change in mortality rate (survival time, hazard ratio) or risk factor prevalence (odds ratio) per year of additional education using multivariable Cox and logistic regression.
Significant inequalities in mortality were found for all causes of death in men and for most causes in women. Inequalities were largest in men for causes related to smoking and alcohol use and in women for circulatory diseases. Gradients in all-cause mortality were more pronounced in younger and middle-aged men, especially in German-speaking Switzerland. Mortality inequalities tended to be larger in German-speaking Switzerland whereas inequalities in associated risk factors were generally more pronounced in French-speaking Switzerland.
With respect to inequalities in mortality and associated risk factors, we found characteristic differences between German- and French-speaking Switzerland, some of which followed gradients described in Europe. These differences only partially reflected inequalities in associated risk factors.
PMCID: PMC2955004  PMID: 20858293
6.  Does the HPV vaccination programme have implications for cervical screening programmes in the UK?☆ 
Vaccine  2014;32(16):1828-1833.
•Women who did not take up the HPV vaccination were less likely to attend for cervical screening.•HPV vaccinated women who attended cervical screening had the lowest proportion of cytological abnormalities detected.•Social deprivation was the main factor-affecting uptake of both HPV vaccination and cervical screening.
In the UK, a national HPV immunisation programme was implemented in 2008 for girls aged 12–13 years. In addition a catch-up programme was implemented for older girls up to 18 years of age from 2009 to 2011, with an uptake rate of 49.4%. Information about future uptake of cervical screening according to vaccination statistics is important in order to understand the impact of the vaccination programme and implications for a national cervical screening programme. We analysed data on a cohort of women who had been offered the HPV vaccine in the catch-up programme and were invited for cervical screening between 2010 and 2012 in Wales (n = 30,882), in a record-linked database study, to describe the cervical screening uptake and clinical outcome according to HPV vaccination status.
In our cohort, 48.5% (n = 14,966) women had had HPV vaccination and 45.9% (n = 14,164) women attended for cervical screening. Women who were unvaccinated were less likely to attend cervical screening (adjusted OR 0.58; 95% CI (0.55, 0.61)). Of those who attended for screening, 13.9% of vaccinated women had abnormal cytology reported compared to 16.7% of women who were unvaccinated. Women who lived in areas with high levels of social deprivation were less likely to be vaccinated (Quintile 5 OR 0.48 95% CI (0.45, 0.52)) or attend cervical screening (Quintile 5 OR 0.70; 95% CI (0.65, 0.75)) compared to those who lived in the least deprived areas.
These data highlight the need for new strategies to address inequalities in cervical screening uptake and can inform further mathematical modelling work to clarify the impact of the HPV vaccination programme on future cervical cancer incidence.
PMCID: PMC3991313  PMID: 24530938
7.  Linking of Primary Care Records to Census Data to Study the Association between Socioeconomic Status and Cancer Incidence in Southern Europe: A Nation-Wide Ecological Study 
PLoS ONE  2014;9(10):e109706.
Area-based measures of economic deprivation are seldom applied to large medical records databases to establish population-scale associations between deprivation and disease.
To study the association between deprivation and incidence of common cancer types in a Southern European region.
Retrospective ecological study using the SIDIAP (Information System for the Development of Research in Primary Care) database of longitudinal electronic medical records for a representative population of Catalonia (Spain) and the MEDEA index based on urban socioeconomic indicators in the Spanish census. Study outcomes were incident cervical, breast, colorectal, prostate, and lung cancer in 2009–2012. The completeness of SIDIAP cancer recording was evaluated through linkage of a geographic data subset to a hospital cancer registry. Associations between MEDEA quintiles and cancer incidence was evaluated using zero-inflated Poisson regression adjusted for sex, age, smoking, alcoholism, obesity, hypertension, and diabetes.
SIDIAP sensitivity was 63% to 92% for the five cancers studied. There was direct association between deprivation and lung, colorectal, and cervical cancer: incidence rate ratios (IRR) 1.82 [1.64–2.01], IRR 1.60 [1.34–1.90], IRR 1.22 [1.07–1.38], respectively, comparing the most deprived to most affluent areas. In wealthy areas, prostate and breast cancers were more common: IRR 0.92 [0.80–1.00], IRR 0.91 [0.78–1.06]. Adjustment for confounders attenuated the association with lung cancer risk (fully adjusted IRR 1.16 [1.08–1.25]), reversed the direction of the association with colorectal cancer (IRR 0.90 [0.84–0.95]), and did not modify the associations with cervical (IRR 1.27 [1.11–1.45]), prostate (0.74 [0.69–0.80]), and breast (0.76 [0.71–0.81]) cancer.
Deprivation is associated differently with the occurrence of various cancer types. These results provide evidence that MEDEA is a useful, area-based deprivation index for analyses of the SIDIAP database. This information will be useful to improve screening programs, cancer prevention and management strategies, to reach patients more effectively, particularly in deprived urban areas.
PMCID: PMC4203762  PMID: 25329578
8.  Does the ‘Scottish effect’ apply to all ethnic groups? All-cancer, lung, colorectal, breast and prostate cancer in the Scottish Health and Ethnicity Linkage Cohort Study 
BMJ Open  2012;2(5):e001957.
Background and objectives
Although ethnic group variations in cancer exist, no multiethnic, population-based, longitudinal studies are available in Europe. Our objectives were to examine ethnic variation in all-cancer, and lung, colorectal, breast and prostate cancers.
Design, setting, population, measures and analysis
This retrospective cohort study of 4.65 million people linked the 2001 Scottish Census (providing ethnic group) to cancer databases. With the White Scottish population as reference (value 100), directly age standardised rates and ratios (DASR and DASRR), and risk ratios, by sex and ethnic group with 95% CI were calculated for first cancers. In the results below, 95% CI around the DASRR excludes 100. Eight indicators of socio-economic position were assessed as potential confounders across all groups.
For all cancers the White Scottish population (100) had the highest DASRRs, Indians the lowest (men 45.9 and women 41.2) and White British (men 87.6 and women 87.3) and other groups were intermediate (eg, Chinese men 57.6). For lung cancer the DASRRs for Pakistani men (45.0), and women (53.5), were low and for any mixed background men high (174.5). For colorectal cancer the DASRRs were lowest in Pakistanis (men 32.9 and women 68.9), White British (men 82.4 and women 83.7), other White (men 77.2 and women 74.9) and Chinese men (42.6). Breast cancer in women was low in Pakistanis (62.2), Chinese (63.0) and White Irish (84.0). Prostate cancer was lowest in Pakistanis (38.7), Indian (62.6) and White Irish (85.4). No socio-economic indicator was a valid confounding variable across ethnic groups.
The ‘Scottish effect’ does not apply across ethnic groups for cancer. The findings have implications for clinical care, prevention and screening, for example, responding appropriately to the known low uptake among South Asian populations of bowel screening might benefit from modelling of cost-effectiveness of screening, given comparatively low cancer rates.
PMCID: PMC3467629  PMID: 23012329
9.  Prospective study of predictors of attendance for breast screening in inner London. 
OBJECTIVE--To investigate the predictors of first-round attendance for breast screening in an inner city area. DESIGN--Prospective design in which women were interviewed or completed a postal questionnaire before being sent their invitation for breast screening. Sociodemographic factors, health behaviours, and attitudes, beliefs, and intentions were used as predictors of subsequent attendance. A randomised control group was included to assess the effect of being interviewed on attendance. SETTING--Three neighbouring health districts in inner south east London. PARTICIPANTS--A total of 3291 women aged 50-64 years who were due to be called for breast screening for the first time. The analysis of predictors was based on a subsample of 1301, reflecting a response rate of 75% to interview and 36% to postal questionnaire. MAIN RESULTS--Attendance was 42% overall, and 70% in those who gave an interview or returned a questionnaire. There was little evidence for an interview effect on attendance. The main findings from the analysis of predictors are listed below. (These were necessarily based on those women who responded to interview/questionnaire and so may not be generalisable to the full sample.) (1) Sociodemographic factors: Women in rented accommodation were less likely to go for screening but other indicators of social class and education were not predictive of attendance. Age and other risk factors for breast cancer were unrelated to attendance, as was the distance between home and the screening centre. Married or single women were more likely to attend than divorced, separated, or widowed women, and black women had a higher than average attendance rate; however, neither of these relationships was found in the interview sample. (2) Health behaviours: Attenders were less likely to have had a recent breast screen, more likely to have had a cervical smear, more likely to go to the dentist for check ups, and differed from non-attenders with regard to drinking frequency. Exercise, smoking, diet change, and breast self-examination were unrelated to attendance. (3) Attitudes, beliefs, and intentions: The two best predictors were measures of the perceived importance of regular screening for cervical and breast cancer and intentions to go for breast screening. Also predictive were beliefs about the following: the personal consequences of going for breast screening, the effectiveness of breast screening, the chances of getting breast cancer, and the attitudes of significant others (the woman's husband/partner and children). Women who reported a moderate amount of worry about breast cancer were more likely to attend than those at the two extremes. CONCLUSIONS--Attenders and non-attenders differ in two broad areas: the health related behaviours they engage in and the attitudes, beliefs, and intentions they have towards breast cancer and breast screening. The latter are potentially amenable to change, and though different factors may operate among women who do not respond to questionnaires, the findings offer hope that attendance rates can be improved by targeting the relevant attitudes and beliefs. This could be done by changing the invitation letter and its accompanying literature, through national and local publicity campaigns, and by advice given by GPs, practice nurses, and other health professionals. It is essential that such interventions are properly evaluated, preferably in randomised controlled studies.
PMCID: PMC1059897  PMID: 8138773
10.  Canadian National Breast Screening Study: 2. Breast cancer detection and death rates among women aged 50 to 59 years. 
OBJECTIVE: To evaluate the efficacy of annual mammography over and above annual physical examination of the breasts and the teaching of breast self-examination among women aged 50 to 59 on entry. DESIGN: Individually randomized controlled trial. SETTING: Fifteen urban centres in Canada with expertise in the diagnosis and treatment of breast cancer. PARTICIPANTS: Women with no history of breast cancer and no mammography in the previous 12 months were randomly assigned to undergo either annual mammography and physical examination (MP group) or annual physical examination only (PO group). The 39,405 women enrolled from January 1980 through March 1985 were followed for a mean of 8.3 years. DATA COLLECTION: Derived from the participants by initial and annual self-administered questionnaires, from the screening examinations, from the patients' physicians, from the provincial cancer registries and by record linkage to the Canadian National Mortality Data Base. Expert panels evaluated histologic and death data. MAIN OUTCOME MEASURES: Rates of referral from screening, rates of detection of breast cancer from screening and from community care, nodal status, tumour size and rates of death from all causes and from breast cancer. RESULTS: Over 85% of the women in each group attended the screening sessions after screen 1. The characteristics of the women in the two groups were similar. Compared with the Canadian population the participants were more likely to be married, have fewer children, have more education, be in a professional occupation, smoke less and have been born in North America. The rate of screen-detected breast cancer on first examination was 7.20 per 1000 in the MP group and 3.45 per 1000 in the PO group, more node-positive tumours were found in the MP group than in the PO group. At subsequent screens the detection rates were a little less than half the rates at screen 1. During years 2 through 5 the ratios of observed to expected cases of invasive breast cancer were 1.28 in the MP group and 1.18 in the PO group. Of the women with invasive breast cancer through to 7 years, 217 in the MP group and 184 in the PO group had no node involvement, 66 and 56 had one to three nodes involved, 32 and 34 had four or more nodes involved, and 55 and 46 had an unknown nodal status. There were 38 deaths from breast cancer in the MP group and 39 in the PO group. The ratio of the proportions of death from breast cancer in the MP group compared with those in the UC group was 0.97 (95% confidence interval 0.62 to 1.52). The survival rates were similar in the two groups. Women whose cancer had been detected by mammography alone had the highest survival rate. CONCLUSION: The study was internally valid, and there was no evidence of randomization bias. Screening with yearly mammography in addition to physical examination of the breasts detected considerably more node-negative, small tumours than screening with physical examination alone, but it had no impact on the rate of death from breast cancer up to 7 years' follow-up from entry.
PMCID: PMC1336544  PMID: 1423088
11.  Ultrasound Screening for Abdominal Aortic Aneurysm 
Executive Summary
The aim of this review was to assess the effectiveness of ultrasound screening for asymptomatic abdominal aortic aneurysm (AAA).
Clinical Need
Abdominal aortic aneurysm is a localized abnormal dilatation of the aorta greater than 3 cm. In community surveys, the prevalence of AAA is reported to be between 2% and 5.4%. Abdominal aortic aneurysms are found in 4% to 8% of older men and in 0.5% to 1.5% of women aged 65 years and older. Abdominal aortic aneurysms are largely asymptomatic. If left untreated, the continuing extension and thinning of the vessel wall may eventually result in rupture of the AAA. Often rupture may occur without warning, causing acute pain. Rupture is always life threatening and requires emergency surgical repair of the ruptured aorta. The risk of death from ruptured AAA is 80% to 90%. Over one-half of all deaths attributed to a ruptured aneurysm take place before the patient reaches hospital. In comparison, the rate of death in people undergoing elective surgery is 5% to 7%; however, symptoms of AAA rarely occur before rupture. Given that ultrasound can reliably visualize the aorta in 99% of the population, and its sensitivity and specificity for diagnosing AAA approaches 100%, screening for aneurysms is worth considering as it may reduce the incidence of ruptured aneurysms and hence reduce unnecessary deaths caused by AAA-attributable mortality.
Review Strategy
The Medical Advisory Secretariat used its standard search strategy to retrieve international health technology assessments and English-language journal articles from selected databases to determine the effectiveness of ultrasound screening for abdominal aortic aneurysms. Case reports, letters, editorials, nonsystematic reviews, non-human studies, and comments were excluded.
Questions asked:
Is population-based AAA screening effective in improving health outcomes in asymptomatic populations?
Is AAA screening acceptable to the population? Does this affect the effectiveness the screening program?
How often should population-based screening occur?
What are appropriate treatment options after screening based on the size of aneurysms?
Are there differences between universal and targeted screening strategies?
What are the harms of screening?
Summary of Findings
Population-based ultrasound screening is effective in men aged 65 to 74 years, particularly in those with a history of smoking. Screening reduces the incidence of AAA ruptures, and decreases rates of emergency surgical repair for AAA and AAA-attributable mortality.
Acceptance rates decline with increasing age and are lower for women. Low acceptance rates may affect the effectiveness of a screening program.
A one-time screen is sufficient for a population-based screening program with regard to initial negative scans and development of large AAAs.
There is no difference between early elective surgical repair and surveillance for small aneurysms (4.0–5.4 cm). Repeated surveillance of small aneurysms is recommended.
Targeted screening based on history of smoking has been found to detect 89% of prevalent AAAs and increase the efficiency of screening programs from statistical modeling data.
Women have not been studied for AAA screening programs. There is evidence suggesting that screening women for AAA should be considered with respect to mortality and case fatality rates in Ontario. It is important that further evaluation of AAAs in women occur.
There is a small risk of physical harm from screening. Less than 1% of aneurysms will not be visualized on initial screen and a re-screen may be necessary; elective surgical repair is associated with a 6% operative morality rate and about 3% of small aneurysms may rupture during surveillance. These risks should be communicated through informed consent prior to screening.
There is little evidence of severe psychological harms associated with screening.
Based on this review, the Medical Advisory Secretariat concluded that there is sufficient evidence to determine that AAA screening using ultrasound is effective and reduces negative health outcomes associated with the condition.
Moreover, screening for AAA is cost-effective, comparing favorably for the cost of per life year gained for screening programs for cervical cancer, hypertension, and breast cancer that are in practice in Ontario, with a high degree of compliance, and can be undertaken with a minimal effort at fewer than 10 minutes to screen each patient.
Overall, the clinical utility of an invitation to use ultrasound screening to identify AAA in men aged 65 to 74 is effective at reducing AAA-attributable mortality. The benefit of screening women is not yet established. However, Ontario data indicate several areas of concern including population prevalence, detection of AAA in women, and case management of AAA in women in terms of age cutoffs for screening and natural history of disease associated with age of rupture.
PMCID: PMC3379169  PMID: 23074490
12.  Establishing a follow-up of the Swiss MONICA participants (1984-1993): record linkage with census and mortality data 
BMC Public Health  2010;10:562.
To assess the feasibility and quality of an anonymous linkage of 1) MONICA (MONItoring of trends and determinants in CArdiovscular disease, three waves between 1984 and 1993) data with 2) census and mortality records of the Swiss National Cohort in order to establish a mortality follow-up until 2008. Many countries feature the defect of lacking general population cohorts because they have missed to provide for follow-up information of health surveys.
Record linkage procedures were used in a multi-step approach. Kaplan-Meier curves from our data were contrasted with the survival probabilities expected from life tables for the general population, age-standardized mortality rates from our data with those derived from official cross-sectional mortality data. Cox regression models were fit to investigate the influence of covariates on survival.
97.8% of the eligible 10,160 participants (25-74y at baseline) could be linked to a census (1990: 9,737; 2000: 8,749), mortality (1,526, 1984-2008) and/or emigration record (320, 1990-2008). Linkage success did not differ by any key study characteristic. Results of survival analyses were robust to linkage step or certainty of a correct link. Loss to follow-up between 1990 and 2000 amounted to 4.7%. MONICA participants had lower mortality than the general population, but similar mortality patterns, (e.g. variation by educational level, marital status or region).
Using anonymized census and death records allowed an almost complete mortality follow-up of MONICA study participants of up to 25 years. Lower mortality compared to the general population was in line with a presumable ‚healthy participant' selection in the original MONICA study. Apart from that, the derived data set reproduced known mortality patterns and showed only negligible potential for selection bias introduced by the linkage process. Anonymous record linkage was feasible and provided robust results. It can thus provide valuable information, when no cohort study is available.
PMCID: PMC2955001  PMID: 20858236
13.  Canadian National Breast Screening Study: 1. Breast cancer detection and death rates among women aged 40 to 49 years. 
OBJECTIVES: To evaluate the efficacy of the combination of annual screening with mammography, physical examination of the breasts and the teaching of breast self-examination in reducing the rate of death from breast cancer among women aged 40 to 49 years on entry. DESIGN: Individually randomized controlled trial. SETTING: Fifteen urban centres in Canada with expertise in the diagnosis and treatment of breast cancer. PARTICIPANTS: Women with no history of breast cancer and no mammography in the previous 12 months were randomly assigned to undergo either annual mammography and physical examination (MP group) or usual care after an initial physical examination (UC group). The 50,430 women enrolled from January 1980 through March 1985 were followed for a mean of 8.5 years. DATA COLLECTION: Derived from the participants by initial and annual self-administered questionnaires, from the screening examinations, from the patients' physicians, from the provincial cancer registries and by record linkage to the Canadian National Mortality Data Base. Expert panels evaluated histologic and death data. MAIN OUTCOME MEASURES: Rates of referral from screening, rates of detection of breast cancer from screening and from community care, nodal status, tumour size, and rates of death from all causes and from breast cancer. RESULTS: Over 90% of the women in each group attended the screening sessions or returned the annual questionnaires, or both, over years 2 to 5. The characteristics of the women in the two groups were similar. Compared with the Canadian population, the participants were more likely to be married, have fewer children, have more education, be in a professional occupation, smoke less and have been born in North America. The rate of screen-detected breast cancer on first examination was 3.89 per 1000 in the MP group and 2.46 per 1000 in the UC group; more node-positive tumours were found in the MP group than in the UC group. During years 2 through 5 the ratios of observed to expected cases of invasive breast cancer were 1.26 in the MP group and 1.02 in the UC group. Of the women with invasive breast cancer through to 7 years, 191 and 157 women in the MP and UC groups respectively had no node involvement, 55 and 43 had one to three nodes involved, 47 and 23 had four or more nodes involved, and 38 and 49 had an unknown nodal status. There were 38 deaths from breast cancer in the MP group and 28 in the UC group. The ratio of the proportions of death from breast cancer in the MP group compared with those in the UC group was 1.36 (95% confidence interval 0.84 to 2.21). The survival rates were similar in the two groups. The highest survival rate occurred among women whose cancer had been detected by mammography alone. CONCLUSION: The study was internally valid, and there was no evidence of randomization bias. Screening with yearly mammography and physical examination of the breasts detected considerably more node-negative, small tumours than usual care, but it had no impact on the rate of death from breast cancer up to 7 years' follow-up from entry.
PMCID: PMC1336543  PMID: 1423087
14.  A systematic review of interventions to increase breast and cervical cancer screening uptake among Asian women 
BMC Public Health  2012;12:413.
The Asian population is one of the fastest growing ethnic minority groups in western countries. However, cancer screening uptake is consistently lower in this group than in the native-born populations. As a first step towards developing an effective cancer screening intervention program targeting Asian women, we conducted a comprehensive systematic review, without geographic, language or date limitations, to update current knowledge on the effectiveness of existing intervention strategies to enhance breast and cervical screening uptake in Asian women.
This study systematically reviewed studies published as of January 2010 to synthesize knowledge about effectiveness of cancer screening interventions targeting Asian women. Fifteen multidisciplinary peer-reviewed and grey literature databases were searched to identify relevant studies.
The results of our systematic review were reported in accordance with the PRISMA Statement. Of 37 selected intervention studies, only 18 studies included valid outcome measures (i.e. self-reported or recorded receipt of mammograms or Pap smear). 11 of the 18 intervention studies with valid outcome measures used multiple intervention strategies to target individuals in a specific Asian ethnic group. This observed pattern of intervention design supports the hypothesis that employing a combination of multiple strategies is more likely to be successful than single interventions. The effectiveness of community-based or workplace-based group education programs increases when additional supports, such as assistance in scheduling/attending screening and mobile screening services are provided. Combining cultural awareness training for health care professionals with outreach workers who can help healthcare professionals overcome language and cultural barriers is likely to improve cancer screening uptake. Media campaigns and mailed culturally sensitive print materials alone may be ineffective in increasing screening uptake. Intervention effectiveness appears to vary with ethnic population, methods of program delivery, and study setting.
Despite some limitations, our review has demonstrated that the effectiveness of existing interventions to promote breast and cervical cancer screening uptake in Asian women may hinge on a variety of factors, such as type of intervention and study population characteristics. While some studies demonstrated the effectiveness of certain intervention programs, the cost effectiveness and long-term sustainability of these programs remain questionable. When adopting an intervention program, it is important to consider the impacts of social-and cultural factors specific to the Asian population on cancer screening uptake. Future research is needed to develop new interventions and tools, and adopt vigorous study design and evaluation methodologies to increase cancer screening among Asian women to promote population health and health equity.
PMCID: PMC3488494  PMID: 22676147
15.  Occupational mortality of women aged 15-59 years at death in England and Wales. 
STUDY OBJECTIVE--The aim was to analyse occupational mortality differences among women using follow up data from a large nationally representative sample. DESIGN--Occupational information was obtained from the 1971 census records of women in the Longitudinal Study carried out by the Office of Population Censuses and Surveys (OPCS) and related to their subsequent mortality in the period between the 1971 and 1981 censuses. SETTING--In the Longitudinal Study, census, vital statistics, and other OPCS records are linked for a 1% sample of the population of England and Wales. The women studied in this paper were drawn from the 513,071 persons in the 1971 census who were included in the Longitudinal Study and whose entries were traced at the National Health Service Central Register by 1977. PARTICIPANTS--The analysis was based on 77,081 women aged 15-59 years in the Longitudinal Study for whom occupational information was collected in the 1971 census (99% of whom were in paid employment in the week before the census). There were 1553 deaths among these women in the follow up period analysed here. MEASUREMENTS AND MAIN RESULTS--Numbers of deaths in each occupational group at census were compared to those expected on the basis of age specific death rates among all women in the study. "Professional, technical workers, and artists" had significantly low mortality while "Engineering and allied trades workers nec" had significantly high mortality. Among the latter, cancer mortality of electrical production process workers was extremely high. A number of other cause specific associations (which appear to confirm proportionate Decennial Supplement analyses) were suggested by the data; examples include high levels of mortality from ischaemic heart disease among cooks, lung cancer and respiratory disease among charwomen and cleaners, and accidents, poisonings, and violence among several groups of professional and technical workers. CONCLUSIONS--By using prospective follow up from the census, occupational differences in mortality can be identified among women in paid employment. As follow up of this study continues, numbers of deaths available for analysis will increase, allowing increasingly comprehensive analyses to be undertaken.
PMCID: PMC1060728  PMID: 2072070
16.  Record linked retrospective cohort study of 4.6 million people exploring ethnic variations in disease: myocardial infarction in South Asians 
BMC Public Health  2007;7:142.
Law and policy in several countries require health services to demonstrate that they are promoting racial/ethnic equality. However, suitable and accurate data are usually not available. We demonstrated, using acute myocardial infarction, that linkage techniques can be ethical and potentially useful for this purpose.
The linkage was based on probability matching. Encryption of a unique national health identifier (the Community Health Index (CHI)) ensured that information about health status and census-based ethnicity could not be ascribed to an identified individual. We linked information on individual ethnic group from the 2001 Census to Scottish hospital discharge and mortality data.
Overall, 94% of the 4.9 million census records were matched to a CHI record with an estimated false positive rate of less than 0.1 %, with 84.9 – 87.6% of South Asians being successfully linked. Between April 2001 and December 2003 there were 126 first episodes of acute myocardial infarction (AMI) among South Asians and 30,978 among non-South Asians. The incidence rate ratio was 1.45 (95% CI 1.17, 1.78) for South Asian compared to non-South Asian men and 1.80 (95% CI 1.31, 2.48) for South Asian women. After adjustment for age, sex and any previous admission for diabetes the hazard ratio for death following AMI was 0.59 (95% CI 0.43, 0.81), reflecting better survival among South Asians.
The technique met ethical, professional and legal concerns about the linkage of census and health data and is transferable internationally wherever the census (or population register) contains ethnic group or race data. The outcome is a retrospective cohort study. Our results point to increased incidence rather than increased case fatality in explaining high CHD mortality rate. The findings open up new methods for researchers and health planners.
PMCID: PMC1965474  PMID: 17615055
17.  Risk Prediction for Breast, Endometrial, and Ovarian Cancer in White Women Aged 50 y or Older: Derivation and Validation from Population-Based Cohort Studies 
PLoS Medicine  2013;10(7):e1001492.
Ruth Pfeiffer and colleagues describe models to calculate absolute risks for breast, endometrial, and ovarian cancers for white, non-Hispanic women over 50 years old using easily obtainable risk factors.
Please see later in the article for the Editors' Summary
Breast, endometrial, and ovarian cancers share some hormonal and epidemiologic risk factors. While several models predict absolute risk of breast cancer, there are few models for ovarian cancer in the general population, and none for endometrial cancer.
Methods and Findings
Using data on white, non-Hispanic women aged 50+ y from two large population-based cohorts (the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial [PLCO] and the National Institutes of Health–AARP Diet and Health Study [NIH-AARP]), we estimated relative and attributable risks and combined them with age-specific US-population incidence and competing mortality rates. All models included parity. The breast cancer model additionally included estrogen and progestin menopausal hormone therapy (MHT) use, other MHT use, age at first live birth, menopausal status, age at menopause, family history of breast or ovarian cancer, benign breast disease/biopsies, alcohol consumption, and body mass index (BMI); the endometrial model included menopausal status, age at menopause, BMI, smoking, oral contraceptive use, MHT use, and an interaction term between BMI and MHT use; the ovarian model included oral contraceptive use, MHT use, and family history or breast or ovarian cancer. In independent validation data (Nurses' Health Study cohort) the breast and ovarian cancer models were well calibrated; expected to observed cancer ratios were 1.00 (95% confidence interval [CI]: 0.96–1.04) for breast cancer and 1.08 (95% CI: 0.97–1.19) for ovarian cancer. The number of endometrial cancers was significantly overestimated, expected/observed = 1.20 (95% CI: 1.11–1.29). The areas under the receiver operating characteristic curves (AUCs; discriminatory power) were 0.58 (95% CI: 0.57–0.59), 0.59 (95% CI: 0.56–0.63), and 0.68 (95% CI: 0.66–0.70) for the breast, ovarian, and endometrial models, respectively.
These models predict absolute risks for breast, endometrial, and ovarian cancers from easily obtainable risk factors and may assist in clinical decision-making. Limitations are the modest discriminatory ability of the breast and ovarian models and that these models may not generalize to women of other races.
Please see later in the article for the Editors' Summary
Editors' Summary
In 2008, just three types of cancer accounted for 10% of global cancer-related deaths. That year, about 460,000 women died from breast cancer (the most frequently diagnosed cancer among women and the fifth most common cause of cancer-related death). Another 140,000 women died from ovarian cancer, and 74,000 died from endometrial (womb) cancer (the 14th and 20th most common causes of cancer-related death, respectively). Although these three cancers originate in different tissues, they nevertheless share many risk factors. For example, current age, age at menarche (first period), and parity (the number of children a woman has had) are all strongly associated with breast, ovarian, and endometrial cancer risk. Because these cancers share many hormonal and epidemiological risk factors, a woman with a high breast cancer risk is also likely to have an above-average risk of developing ovarian or endometrial cancer.
Why Was This Study Done?
Several statistical models (for example, the Breast Cancer Risk Assessment Tool) have been developed that estimate a woman's absolute risk (probability) of developing breast cancer over the next few years or over her lifetime. Absolute risk prediction models are useful in the design of cancer prevention trials and can also help women make informed decisions about cancer prevention and treatment options. For example, a woman at high risk of breast cancer might decide to take tamoxifen for breast cancer prevention, but ideally she needs to know her absolute endometrial cancer risk before doing so because tamoxifen increases the risk of this cancer. Similarly, knowledge of her ovarian cancer risk might influence a woman's decision regarding prophylactic removal of her ovaries to reduce her breast cancer risk. There are few absolute risk prediction models for ovarian cancer, and none for endometrial cancer, so here the researchers develop models to predict the risk of these cancers and of breast cancer.
What Did the Researchers Do and Find?
Absolute risk prediction models are constructed by combining estimates for risk factors from cohorts with population-based incidence rates from cancer registries. Models are validated in an independent cohort by testing their ability to identify people with the disease in an independent cohort and their ability to predict the observed numbers of incident cases. The researchers used data on white, non-Hispanic women aged 50 years or older that were collected during two large prospective US cohort studies of cancer screening and of diet and health, and US cancer incidence and mortality rates provided by the Surveillance, Epidemiology, and End Results Program to build their models. The models all included parity as a risk factor, as well as other factors. The model for endometrial cancer, for example, also included menopausal status, age at menopause, body mass index (an indicator of the amount of body fat), oral contraceptive use, menopausal hormone therapy use, and an interaction term between menopausal hormone therapy use and body mass index. Individual women's risk for endometrial cancer calculated using this model ranged from 1.22% to 17.8% over the next 20 years depending on their exposure to various risk factors. Validation of the models using data from the US Nurses' Health Study indicated that the endometrial cancer model overestimated the risk of endometrial cancer but that the breast and ovarian cancer models were well calibrated—the predicted and observed risks for these cancers in the validation cohort agreed closely. Finally, the discriminatory power of the models (a measure of how well a model separates people who have a disease from people who do not have the disease) was modest for the breast and ovarian cancer models but somewhat better for the endometrial cancer model.
What Do These Findings Mean?
These findings show that breast, ovarian, and endometrial cancer can all be predicted using information on known risk factors for these cancers that is easily obtainable. Because these models were constructed and validated using data from white, non-Hispanic women aged 50 years or older, they may not accurately predict absolute risk for these cancers for women of other races or ethnicities. Moreover, the modest discriminatory power of the breast and ovarian cancer models means they cannot be used to decide which women should be routinely screened for these cancers. Importantly, however, these well-calibrated models should provide realistic information about an individual's risk of developing breast, ovarian, or endometrial cancer that can be used in clinical decision-making and that may assist in the identification of potential participants for research studies.
Additional Information
Please access these websites via the online version of this summary at
This study is further discussed in a PLOS Medicine Perspective by Lars Holmberg and Andrew Vickers
The US National Cancer Institute provides comprehensive information about cancer (in English and Spanish), including detailed information about breast cancer, ovarian cancer, and endometrial cancer;
Information on the Breast Cancer Risk Assessment Tool, the Surveillance, Epidemiology, and End Results Program, and on the prospective cohort study of screening and the diet and health study that provided the data used to build the models is also available on the NCI site
Cancer Research UK, a not-for-profit organization, provides information about cancer, including detailed information on breast cancer, ovarian cancer, and endometrial cancer
The UK National Health Service Choices website has information and personal stories about breast cancer, ovarian cancer, and endometrial cancer; the not-for-profit organization Healthtalkonline also provides personal stories about dealing with breast cancer and ovarian cancer
PMCID: PMC3728034  PMID: 23935463
18.  Cervical cancer screening of underserved women in the United States: results from the National Breast and Cervical Cancer Early Detection Program, 1997–2012 
Cancer Causes & Control  2015;26(5):671-686.
The National Breast and Cervical Cancer Early Detection Program (NBCCEDP) provides breast and cervical cancer screens to low-income, uninsured, and underinsured women. We describe the number and proportion of women eligible for cervical cancer screening services and the proportion of eligible women screened over the period 1997–2012.
Low-income, uninsured, and underinsured women aged 18–64 years who have not had a hysterectomy are eligible for cervical cancer screening through the NBCCEDP. We estimated the number of low-income, uninsured women using data from the US Census Bureau. We adjusted our estimates for hysterectomy status using the National Health Interview Survey and the Behavioral Risk Factor Surveillance System. We used data from the NBCCEDP to describe the number of women receiving NBCCEDP-funded screening and calculated the proportion of eligible women who received screening through the NBCCEDP at the national level (by age group, race/ethnicity) and at the state level by age group. We used the Medical Expenditure Panel Survey to estimate the proportion of NBCCEDP-eligible women who were screened outside the NBCCEDP and the proportion that are not screened.
We estimate that in 2010–2012, 705,970 women aged 18–64 years, 6.5 % (705,970 of 9.8 million) of the eligible population, received NBCCEDP-funded Pap tests. We estimate that 60.2 % of eligible women aged 18–64 years were screened outside the NBCCEDP and 33.3 % were not screened. The NBCCEDP provided 623,603 screens to women aged 40–64 years, an estimated 16.5 % of the eligible population, and 83,660 screens to women aged 18–39 years, representing an estimated 1.2 % of the eligible population. The estimated proportions of eligible women screened in each state ranged from 1.5 to 32.7 % and 5 % to 73.2 % among the 18–64 and 40–64 years age groups, respectively. Changes in the proportion of eligible women screened over the study period were nonsignificant.
Although the program provided cervical screening to over 700,000 women between 2010 and 2012, it served a small percent of those eligible. The proportion of women screened varied substantially across age groups, racial/ethnic groups, and states. Many low-income, uninsured women are not being screened.
PMCID: PMC4429146  PMID: 25783455
Cervical cancer; Papanicolaou test utilization; Screening proportions; Medically underserved; National Breast and Cervical Cancer Early Detection Program
19.  Impact of socioeconomic status on cancer incidence and stage at diagnosis: selected findings from the surveillance, epidemiology, and end results: National Longitudinal Mortality Study 
Cancer causes & control : CCC  2008;20(4):10.1007/s10552-008-9256-0.
Population-based cancer registry data from the Surveillance, Epidemiology, and End Results (SEER) Program at the National Cancer Institute (NCI) are mainly based on medical records and administrative information. Individual-level socioeconomic data are not routinely reported by cancer registries in the United States because they are not available in patient hospital records. The U.S. representative National Longitudinal Mortality Study (NLMS) data provide self-reported, detailed demographic and socioeconomic data from the Social and Economic Supplement to the Census Bureau's Current Population Survey (CPS). In 1999, the NCI initiated the SEER-NLMS study, linking the population-based SEER cancer registry data to NLMS data. The SEER-NLMS data provide a new unique research resource that is valuable for health disparity research on cancer burden. We describe the design, methods, and limitations of this data set. We also present findings on cancer-related health disparities according to individual-level socioeconomic status (SES) and demographic characteristics for all cancers combined and for cancers of the lung, breast, prostate, cervix, and melanoma.
Records of cancer patients diagnosed in 1973–2001 when residing 1 of 11 SEER registries were linked with 26 NLMS cohorts. The total number of SEER matched cancer patients that were also members of an NLMS cohort was 26,844. Of these 26,844 matched patients, 11,464 were included in the incidence analyses and 15,357 in the late-stage diagnosis analyses. Matched patients (used in the incidence analyses) and unmatched patients were compared by age group, sex, race, ethnicity, residence area, year of diagnosis, and cancer anatomic site. Cohort-based age-adjusted cancer incidence rates were computed. The impact of socioeconomic status on cancer incidence and stage of diagnosis was evaluated.
Men and women with less than a high school education had elevated lung cancer rate ratios of 3.01 and 2.02, respectively, relative to their college educated counterparts. Those with family annual incomes less than $12,500 had incidence rates that were more than 1.7 times the lung cancer incidence rate of those with incomes $50,000 or higher. Lower income was also associated with a statistically significantly increased risk of distant-stage breast cancer among women and distant-stage prostate cancer among men.
Socioeconomic patterns in incidence varied for specific cancers, while such patterns for stage were generally consistent across cancers, with late-stage diagnoses being associated with lower SES. These findings illustrate the potential for analyzing disparities in cancer outcomes according to a variety of individual-level socioeconomic, demographic, and health care characteristics, as well as by area measures available in the linked database.
PMCID: PMC2711979  PMID: 19002764
SEER; NLMS; Cancer incidence; Stage; Education; Income; Poverty; Unemployment; SES; Race/ethnicity; Rural/urban; Health disparities; Record linkage
20.  Methods and feasibility of collecting occupational data for a large population-based cohort study in the United States: the reasons for geographic and racial differences in stroke study 
BMC Public Health  2014;14:142.
Coronary heart disease and stroke are major contributors to preventable mortality. Evidence links work conditions to these diseases; however, occupational data are perceived to be difficult to collect for large population-based cohorts. We report methodological details and the feasibility of conducting an occupational ancillary study for a large U.S. prospective cohort being followed longitudinally for cardiovascular disease and stroke.
Current and historical occupational information were collected from active participants of the REasons for Geographic And Racial Differences in Stroke (REGARDS) Study. A survey was designed to gather quality occupational data among this national cohort of black and white men and women aged 45 years and older (enrolled 2003–2007). Trained staff conducted Computer-Assisted Telephone Interviews (CATI). After a brief pilot period, interviewers received additional training in the collection of narrative industry and occupation data before administering the survey to remaining cohort members. Trained coders used a computer-assisted coding system to assign U.S. Census codes for industry and occupation. All data were double coded; discrepant codes were independently resolved.
Over a 2-year period, 17,648 participants provided consent and completed the occupational survey (87% response rate). A total of 20,427 jobs were assigned Census codes. Inter-rater reliability was 80% for industry and 74% for occupation. Less than 0.5% of the industry and occupation data were uncodable, compared with 12% during the pilot period. Concordance between the current and longest-held jobs was moderately high. The median time to collect employment status plus narrative and descriptive job information by CATI was 1.6 to 2.3 minutes per job. Median time to assign Census codes was 1.3 minutes per rater.
The feasibility of conducting high-quality occupational data collection and coding for a large heterogeneous population-based sample was demonstrated. We found that training for interview staff was important in ensuring that narrative responses for industry and occupation were adequately specified for coding. Estimates of survey administration time and coding from digital records provide an objective basis for planning future studies. The social and environmental conditions of work are important understudied risk factors that can be feasibly integrated into large population-based health studies.
PMCID: PMC3933294  PMID: 24512119
Occupations; Occupational exposure; Stressful events; Social class; Cohort studies; Epidemiologic methods; Data collection; Stroke; Cardiovascular disease
21.  Breast cancer screening uptake among women from different ethnic groups in London: a population-based cohort study 
BMJ Open  2014;4(10):e005586.
To use newly available self-assigned ethnicity information to investigate variation in breast cancer screening uptake for women from the 16 specific ethnic groups within the broad Asian, Black and White groups that previous studies report.
National cancer screening programme services within London.
655 516 female residents aged 50–69, invited for screening between March 2006 and December 2009. Ethnicity information was available for 475 478 (72.5%). White British women were the largest group (306 689, 46.8%), followed by Indian (34 687, 5.3%), White Other (30 053, 4.6%), Black Caribbean (25 607, 3.9%), White Irish (17 271, 2.6%), Black African (17 071, 2.6%) and Asian Other (10 579, 1.6%).
Outcome measures
Uptake for women in different ethnic groups aged 50–52 for a first call invitation to the programme, and for women aged 50–69 for a routine recall invitation after a previous mammography. Uptake is reported (1) for London overall, adjusted using logistic regression, for age at invitation, socioeconomic deprivation and geographical screening area, and (2) for individual areas, adjusted for age and deprivation.
White British women attended their first call (67%) and routine recall (78%) invitations most often. Indian women were more likely to attend their first (61%) or routine recall (74%) than Bangladeshi women (43% and 61%, respectively), and Black Caribbean women were more likely than Black African women to attend first call (63% vs 49%, respectively) and routine recall (74% vs 64%, respectively). There was less variation between ethnic groups in some screening areas.
Breast cancer screening uptake in London varies by specific ethnic group for first and subsequent invitations, with White British women being more likely to attend. The variation in the uptake for women from the same ethnic groups in different geographical areas suggests that collaboration about the successful engagement of services with different communities could improve uptake for all women.
PMCID: PMC4202018  PMID: 25324320
22.  Using geographic methods to inform cancer screening interventions for South Asians in Ontario, Canada 
BMC Public Health  2013;13:395.
Literature suggests that South Asians in Ontario, Canada are under-screened for breast, cervical and colorectal cancer. Accordingly, we are involved in a community-engaged multi-phase study aimed at increasing cancer screening for this vulnerable group. In the work described in this manuscript, we aimed to use visual displays of spatial analyses to identify the most appropriate small geographic areas in which to pilot targeted cancer screening interventions for Ontario’s South Asian community.
We used Geographic Information Systems (GIS), including Local Indicators of Spatial Association (LISA) using GeoDa software, and population-level administrative data to create multi-layered maps of: i) rates of appropriate cancer screening, ii) the percentage of residents of South Asian ethnicity, and iii) the locations of primary care practices and community health centres by census tract in the Peel Region of Ontario (population: 1.2 million). The maps were shared with partner health service and community service organizations at an intervention development workgroup meeting to examine face validity.
The lowest rates of appropriate cancer screening for census tracts across the region were 51.1% for cervical cancer, 48.5% for breast cancer, and 42.5% for colorectal cancer. We found marked variation both in screening rates and in the proportion of South Asians residents by census tract but lower screening rates in the region were consistently associated with larger South Asian populations. The LISA analysis identified a high-risk area consisting of multiple neighbouring census tracts with relatively low screening rates for all three cancer types and with a relatively large South Asian population. Partner organizations recognized and validated the geographic location highlighted by the LISA analysis. Many primary care practices are located in this high-risk area, with one community health centre located very nearby.
In this populous region of Ontario, South Asians are more likely to reside in areas with lower rates of appropriate breast, cervical and colorectal cancer screening. We have identified a high-risk area appropriate for both patient- and provider-focused interventions. Geographic Information Systems, in particular LISA analyses, can be invaluable when working with health service and community organizations to define areas with the greatest need for interventions to reduce health inequities.
PMCID: PMC3640962  PMID: 23622426
23.  Using mortality follow-up of surveys to estimate social inequalities in healthy life years 
The estimation of healthy life years (HLY) by socio-economic status (SES) requires two types of data: the prevalence of activity limitation by SES generally extracted from surveys and mortality rates by SES generally derived from a linkage between the SES information in population databases (census, register) and mortality records. In some situations, no population-wide databases are available to produce mortality rates by SES, and therefore some alternatives must be explored. This paper assesses the validity of calculating HLY by SES using mortality rates derived from a linkage between surveys and mortality records.
Two surveys were chosen to explore the validity of the proposed approach: The Belgian Health Interview Survey (HIS) and the Belgian Survey on Income and Living Conditions (SILC). The mortality follow-up of these surveys were used to calculate HLY by educational level at age 25. These HLY were compared with HLY estimates calculated using the mortality follow-up of the 2001 census. The validity of this approach was evaluated against two criteria. First, the HLY calculated using the census and those calculated using the surveys must not be significantly different. Second, survey-based HLY must show significant social inequalities since such inequalities have been consistently reported with census-based HLY.
Both criteria were met. First, for each educational category, no statistically significant difference was found when comparing census-based and survey-based HLY estimates. For instance, men in the lowest educational category have shown a HLY of 34 years according to the HIS, and while this figure was 35.5 years according to the census, this difference was not statistically significant. Second, the survey-based HLY have shown a significant social gradient. For instance, men in the highest educational category are expected to live 9.5 more HLY than their counterparts in the lowest educational category based on the HIS estimates, compared with 7.3 HLY based on the census estimates.
This article suggests that using the mortality follow-up of a nationally representative cross-sectional survey is a valid approach to monitor social inequalities in HLY in the absence of population-wide data.
PMCID: PMC4030465  PMID: 24855457
Healthy life years; Socioeconomic status; Surveys; Mortality follow-up; Monitoring
24.  The effects of a UK review of Breast Cancer Screening on Uptake: An observational before/after study 
Journal of Medical Screening  2013;20(2):86-90.
To measure whether uptake of breast cancer screening was affected by the publication of the Marmot Review and associated press coverage.
Eight NHS breast screening centres in the West Midlands of the UK.
Uptake of breast cancer screening invitations was compared in the week before and after the Marmot review publication. All 12,023 women invited for screening between 23 October 2012 and 5 November 2012 were included. A mixed effects model of the predictors of screening uptake (on date invited, or within 21 days) was created. Predictors considered for inclusion were whether the allocated screening appointment was before or after publication of the review, population factors (age, index of multiple deprivation income domain by quintile, previous attendance), and interaction terms.
Uptake decreased after publication of the review from 65% to 62% (OR = 0.87 95%CI = 0.80–0.94), but a similar decrease was seen for the same dates on the previous year (OR = 0.85 95%CI = 0.78–0.93). Odds of attending screening were lower for women in the most deprived (uptake = 49%, OR = 0.54, 95%CI = 0.46–0.62) in comparison with the least deprived quintile (uptake = 71%). Odds of attendance also increased if the woman had ever previously attended (OR 3.9 95% CI 3.5–4.4), and decreased with each year of increasing age (OR 0.96 95% CI 0.96–0.97). There were no interactions between any of the other predictors and whether the appointment was before or after publication of the Marmot review.
No change in uptake of breast cancer screening above normal seasonal variation was detected after publication of the Marmot review.
PMCID: PMC3807969  PMID: 24009089
25.  The Health System and Population Health Implications of Large-Scale Diabetes Screening in India: A Microsimulation Model of Alternative Approaches 
PLoS Medicine  2015;12(5):e1001827.
Like a growing number of rapidly developing countries, India has begun to develop a system for large-scale community-based screening for diabetes. We sought to identify the implications of using alternative screening instruments to detect people with undiagnosed type 2 diabetes among diverse populations across India.
Methods and Findings
We developed and validated a microsimulation model that incorporated data from 58 studies from across the country into a nationally representative sample of Indians aged 25–65 y old. We estimated the diagnostic and health system implications of three major survey-based screening instruments and random glucometer-based screening. Of the 567 million Indians eligible for screening, depending on which of four screening approaches is utilized, between 158 and 306 million would be expected to screen as “high risk” for type 2 diabetes, and be referred for confirmatory testing. Between 26 million and 37 million of these people would be expected to meet international diagnostic criteria for diabetes, but between 126 million and 273 million would be “false positives.” The ratio of false positives to true positives varied from 3.9 (when using random glucose screening) to 8.2 (when using a survey-based screening instrument) in our model. The cost per case found would be expected to be from US$5.28 (when using random glucose screening) to US$17.06 (when using a survey-based screening instrument), presenting a total cost of between US$169 and US$567 million. The major limitation of our analysis is its dependence on published cohort studies that are unlikely fully to capture the poorest and most rural areas of the country. Because these areas are thought to have the lowest diabetes prevalence, this may result in overestimation of the efficacy and health benefits of screening.
Large-scale community-based screening is anticipated to produce a large number of false-positive results, particularly if using currently available survey-based screening instruments. Resource allocators should consider the health system burden of screening and confirmatory testing when instituting large-scale community-based screening for diabetes.
Sanjay Basu and colleagues estimate the benefits and costs of scaling up survey- or glucometer-based diabetes screening across India’s diverse populations.
Editors' Summary
Worldwide, 387 million people have diabetes, a chronic condition characterized by high levels of glucose (sugar) in the blood. Blood sugar levels are usually controlled by insulin, a hormone released by the pancreas after meals. In people with type 2 diabetes (the most common type of diabetes), blood sugar control fails because the fat and muscle cells that normally respond to insulin by removing excess sugar from the blood become less responsive to insulin. Risk factors for diabetes include being overweight, having a large waist, being physically inactive, and having a family history of diabetes. The symptoms of diabetes, which develop slowly, include excessive urination at night and unexplained weight loss. Type 2 diabetes can usually be controlled initially with diet and exercise and with antidiabetic drugs such as metformin and sulfonylureas, but many patients eventually need insulin injections. Long-term complications of diabetes, 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?
Diabetes is becoming increasing common, particularly in rapidly developing countries, but most people with diabetes in these countries are unaware that they have the condition. Because the risk of developing diabetic complications is reduced by careful blood sugar control, it is important to identify and treat anyone who has diabetes as early as possible. Some rapidly developing countries are therefore beginning to develop systems for large-scale community-based screening for diabetes (even though the UK has recently decided against such screening). In India, for example, more than 53 million adults living in rural and urban communities have already been screened using either questionnaires designed to provide a risk score (survey-based screening) or random blood glucose testing (glucometer-based screening). People who are identified as “high risk” using these approaches are referred for fasting blood glucose tests to confirm the diagnosis. Although the Indian government plans to expand this screening program, no data have been collected to track its performance. Here, the researchers develop a microsimulation model (a computer model that operates at the level of individuals) to investigate the implications of using alternative screening instruments to identify people with undetected diabetes across diverse populations in India.
What Did the Researchers Do and Find?
The researchers constructed a synthetic nationally representative population of Indians aged 25–65 years using data from 58 sub-national studies. They then used their microsimulation model to estimate the diagnostic and health system implications of using three survey-based screening instruments and glucometer-based screening to identify individuals in this population with diabetes. Depending on which approach was used for screening, between 158 million and 306 million of the 567 million Indians eligible for screening would be classified as high risk for diabetes and would be referred for confirmatory testing, according to the model. However, between 126 million and 273 million of these high-risk individuals would be false positives; only between 26 million and 37 million of these individuals would meet the international diagnostic criteria for diabetes (true positives). The researchers estimate that the cost per case found would vary from US$5.28 (when using random glucose screening) to US$17.06 (when using a survey-based screening instrument). Finally, they estimate that the total cost for screening the eligible population would be between US$169 and US$567 million.
What Do These Findings Mean?
Established criteria for implementing screening programs specify that such programs should use reliable instruments that detect a large proportion of true cases (high sensitivity) and that have a low rate of false positives (high specificity). Screening programs should also offer significant therapeutic benefits to individuals diagnosed through screening. The findings of this study suggest that large-scale community-based screening for diabetes in India using the currently available screening instruments is unlikely to meet these criteria. Indeed, because the data used to construct the synthetic population came from published studies that did not capture the situation in the poorest, most rural areas of India, where the proportion of the population with diabetes is thought to be lowest, these findings may overestimate the efficacy and health benefits of screening. The researchers suggest, therefore, that an approach that focuses on symptom-based screening and on improvements in the treatment of already diagnosed individuals might be a more sensible path for India to take to deal with its burgeoning diabetes epidemic than community-based mass screening.
Additional Information.
Please access these websites via the online version of this summary at The US National Diabetes Information Clearinghouse provides information about diabetes for patients, healthcare professionals, and the general public (in English and Spanish)The UK National Health Service Choices website provides information for patients and caregivers about type 2 diabetes and about living with diabetes; it also provides people’s stories about diabetesThe charity Diabetes UK provides detailed information for patients and caregivers in several languagesThe UK-based non-profit organization HealthTalkOnline has interviews with people about their experiences of diabetesMedlinePlus provides links to further resources and advice about diabetes (in English and Spanish)A statement from the UK National Screening Committee on diabetes screening in adults is available
PMCID: PMC4437977  PMID: 25992895

Results 1-25 (1156426)