Colin Fischbacher

Record linked retrospective cohort study of 4.6 million people exploring ethnic variations in disease: myocardial infarction in South Asians

BackgroundLaw 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.MethodsThe 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.ResultsOverall, 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.ConclusionThe 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.

Mortality from all cancers and lung, colorectal, breast and prostate cancer by country of birth in England and Wales, 2001–2003

Mortality from all cancers combined and major cancers among men and women aged 20 years and over was compared by country of birth with that of the whole of England and Wales as the reference group. Population data from the 2001 Census and mortality data for 2001–2003 were used to estimate standardised mortality ratios. Data on approximately 399u2009000 cancer deaths were available, with at least 400 cancer deaths in each of the smaller populations. Statistically significant differences from the reference group included: higher mortality from all cancers combined, lung and colorectal cancer among people born in Scotland and Ireland, lower mortality for all cancers combined, lung, breast and prostate cancer among people born in Bangladesh (except for lung cancer in men), India, Pakistan or China/Hong Kong, lower lung cancer mortality among people born in West Africa or the West Indies, higher breast cancer mortality among women born in West Africa and higher prostate cancer mortality among men born in West Africa or the West Indies. These data may be relevant to causal hypotheses and in relation to health care and cancer prevention.

Epidemiology and disease burden from allergic disease in Scotland: analyses of national databases.

Summary Background There are ongoing concerns about the quality of care provided to patients with allergic disorders in Scotland, but there are relatively few reliable data on the overall disease burden. We sought to: (1) describe the incidence, prevalence and outcome of allergic disorders; (2) estimate healthcare burden and costs; and (3) investigate ethnic variations in the epidemiology and outcomes from allergic disorders in Scotland. Methods Data sources: national surveys; primary care data; prescribing and medication data; hospital admissions data and mortality data. Results Allergic disorders are extremely common in Scotland, affecting about one in three of the population at some time in their lives. Incidence was highest for eczema (10.2 per 1000 registered patients). Over 4% of all GP consultations and 1.5% of hospital admissions were for allergic disorders. There were 100 asthma deaths in 2005 (20 per million people). Direct healthcare costs for allergic disorders were an estimated £130 million per year, the majority of these being incurred in primary care and related to asthma. Conclusions Allergic disorders are common in Scotland and given the very high proportion of children now affected, the high disease burden associated with these conditions is likely to persist for many decades.

Is there equity of service delivery and intermediate outcomes in South Asians with type 2 diabetes? Analysis of DARTS database and summary of UK publications

BACKGROUNDnThere are doubts whether diabetes care is equitable across UK ethnic groups. We examined processes and outcomes in South Asians with diabetes and reviewed the UK literature.nnnMETHODSnWe used name search methods to identify South Asians in a regional diabetes database. We compared prevalence rates, processes and outcomes of care between November 2003 and December 2004. We used standard literature search techniques.nnnRESULTSnThe prevalence of diabetes in South Asians was 3-4 times higher than non-South Asians. South Asians were 1.11 times (95% confidence interval 1.06, 1.16) more likely to have a structured review. South Asian women were 1.10 times more likely to have a record of body mass index (95% CI 1.04, 1.16). HbA1c levels were 1.03 times higher (95% CI 1.00, 1.06) among South Asians, retinopathy 1.36 times more common (95% CI 1.03, 1.78) and hypertension 0.71 times as common (95% CI 0.58, 0.87).nnnCONCLUSIONSnWe found evidence of equity in many aspects of diabetes care for South Asians in Tayside. The finding of higher HbA1c and more retinopathy among South Asians needs explanation and a service response. These findings from a region with a small non-White population largely support the recent findings from other parts of the UK.

Is the Scottish population living dangerously? Prevalence of multiple risk factors: the Scottish Health Survey 2003

BackgroundRisk factors are often considered individually, we aimed to investigate the prevalence of combinations of multiple behavioural risk factors and their association with socioeconomic determinants.MethodsMultinomial logistic regression was used to model the associations between socioeconomic factors and multiple risk factors from data in the Scottish Health Survey 2003. Prevalence of five key risk - smoking, alcohol, diet, overweight/obesity, and physical inactivity, and their risk in relation to demographic, individual and area socioeconomic factors were assessed.ResultsFull data were available on 6,574 subjects (80.7% of the survey sample). Nearly the whole adult population (97.5%) reported to have at least one behavioural risk factor; while 55% have three or more risk factors; and nearly 20% have four or all five risk factors. The most important determinants for having four or five multiple risk factors were low educational attainment which conferred over a 3-fold increased risk compared to high education; and residence in the most deprived communities (relative to least deprived) which had greater than 3-fold increased risk.ConclusionsThe prevalence of multiple behavioural risk factors was high and the prevalence of absence of all risk factors very low. These behavioural patterns were strongly associated with poorer socioeconomic circumstances. Policy to address factors needs to be joined up and better consider underlying socioeconomic circumstances.

Cohort Profile: Scottish Health and Ethnicity Linkage Study of 4.65 million people exploring ethnic variations in disease in Scotland

: imported for journal id 300 on Dec 03, 2001, no letter sentnnSent to referee - Referee Sent: 16-Nov-00 Expected: 16-Dec-00 Arrived: 12-Dec-00 nMsID: IJE/2000/000462 - Major Revision - Last reminder: nnSent to referee - Referee Sent: 05-Mar-01 Expected: 05-Apr-01 Arrived: 26-Apr-01 nMsID: IJE/2001/000086 - Reject - Last reminder: 06-Apr-01 nnThank you - Referee Sent: Expected: Arrived: nMsID: IJE/2001/000086 - - Last reminder: nnAcknowledgement - Correspond Sent: 04-Jul-01 Expected: Arrived: nMsID: IJE/2001/000382 - - Last reminder: nndecision - Correspond Sent: 30-Jul-01 Expected: Arrived: nMsID: IJE/2001/000382 - - Last reminder: (Bhopal, Raj S)

Measures of socioeconomic position are not consistently associated with ethnic differences in cardiovascular disease in Scotland: methods from the Scottish Health and Ethnicity Linkage Study (SHELS)

BACKGROUNDnEthnic health inequalities are substantial. One explanation relates to socioeconomic differences between groups. However, socioeconomic variables need to be comparable across ethnic groups as measures of socioeconomic position (SEP) and indicators of health outcomes.nnnMETHODSnWe linked self-reported SEP and ethnicity data on 4.65 million individuals from the 2001 Scottish Census to hospital admission and mortality data for cardiovascular disease (CVD). We examined the direction, strength and linearity of association between eight individual, household and area socioeconomic measures and CVD in 10 ethnic groups and the impact of SEP adjustment.nnnRESULTSnThere was wide socioeconomic variation between groups. All eight measures showed consistent, positive associations with CVD in White populations, as did educational qualification in non-White ethnic groups. For other SEP measures, associations tended to be consistent with those of White groups though there were one or two exceptions in each non-White group. Multiple SEP adjustment had little effect on relative risk of CVD for most groups. Where it did, the effect varied in direction and magnitude (for example increasing adjusted risk by 23% in Indian men but attenuating it by 11% among Pakistani women).nnnCONCLUSIONSnAcross groups, SEP measures were inconsistently associated with CVD hospitalization or death, with effect size and direction of effect after adjustment varying across ethnic groups. We recommend that researchers systematically explore the effect of their choice of SEP indicators, using standard multivariate methods where appropriate, to demonstrate their cross-ethnic group validity as potential confounding variables for the specific groups and outcomes of interest.

Variations in all cause and cardiovascular mortality by country of birth in Scotland, 1997-2003

Background and Aims Country of birth provides a proxy for ethnic group for recent migrants. Major differences in mortality by country of birth have been demonstrated in England and Wales, but similar published data for Scotland are lacking. We aimed to examine variations in mortality by country of birth for Scottish residents. Methods We calculated standardised mortality ratios by country of birth for Scottish residents aged 25 years and over between January 1997 and March 2003. Results and Conclusion Comparisons with England and Wales showed high allcause, coronary heart disease (CHD) and stroke mortality among Scottish residents born in Scotland, Northern Ireland, the Republic of Ireland, India and Hong Kong. However, most country of birth groups had similar or lower mortality than the Scottish born. These are the first data on mortality by country of birth in Scotland and they demonstrate major variations. Comparisons within the Scottish population might be interpreted as reassuring, since they do not show the excesses in CHD mortality by country of birth reported in England and Wales. However, the use of England and Wales as a comparison group shows a substantial excess of CHD risk among South Asians in Scotland, comparable to that reported in England and Wales.

Ethnic variations in chest pain and angina in men and women: Scottish Ethnicity and Health Linkage Study of 4.65 million people.

Background: European research on ethnic variations in cardiovascular disease has mostly examined mortality endpoints using country of birth as a proxy for ethnicity. We report on chest pain and angina by ethnic group. Design and methods: Retrospective cohort linking the Census 2001 for Scotland (providing 14 ethnic group categories) and hospital discharge/community and hospital deaths data. Directly age-standardized rates and rate ratios were calculated. Risk ratios were adjusted for age and then highest educational qualification of the individual using Poisson regression. Ratios were multiplied by 100 and 95% confidence intervals (CI) were calculated. The reference was the White Scottish population (100). In the results below, the 95% CI excludes 100. Results: There was raised chest pain mortality/hospital discharge risk in Indian men (rate ratio 141.2), Other South Asian women (rate ratio 140.9), and Pakistanis (rate ratio 216.2 in men, 243.0 in women). Rate ratios were lowest in other White British (rate ratio 76.1 in men, 73.7 in women) and Chinese (rate ratio 67.6 in men, 76.7 in women). Adjustment for age and education attenuated, but did not abolish, differences in other White British (risk ratio from 73.5 to 83.5) and Pakistani (risk ratio from 209.0 to 198.2) male populations and increased them in most others, e.g. other South Asian men (from risk ratio of 128.9 to 140.1). Pakistani populations had the highest risk of angina (rate ratio 189.3 in men, 159.7 in women). Other White British (rate ratio 81.4 for men, 78.0 for women), Other White (rate ratio 89.6 men, 85.2 women), and Chinese (rate ratio 60.5 men, 67.4 women) had the lowest risk. Adjustment for education did not greatly alter these patterns. Conclusions: There were important ethnic variations. The results call for replication elsewhere in Europe and targeted prevention programmes and vigilant diagnosis and management by clinicians.

Ethnic variations in the incidence and mortality of stroke in the Scottish Health and Ethnicity Linkage Study of 4.65 million people

Background: Ethnic variations in stroke require more European studies, especially as differences are reportedly large. Methods: We created a retrospective cohort study of 4.65 million people in Scotland linking ethnicity from the census and stroke incidence and mortality from NHS databases. Rate ratios using direct age standardization and risk ratios were calculated, the latter to model the influence of educational qualification in a Poisson regression model. Results: Age-adjusted rate ratios varied little, compared to the White Scottish group (reference value 100) and the 95% CIs usually included 100, e.g. higher in Pakistani men (120.5, 95% CI 95.2–145.8) and in African men (137.9, 95% CI 91.5–184.4) but not in Pakistani or African women. Stroke rates were low in the Other White British (78.3, 95% CI 75.4−81.2 in men and 84.9, 95% CI 82.0−87.8 in women), Other White (89.8, 95% CI 81.5−98.1 in men and 88.8, 95% CI 80.9−96.7 in women) and Chinese men (70.3, 95% CI 45.7−94.8). Adjusting for highest educational qualification attenuated some and augmented other risk ratios, e.g. in Other White British men, the risk ratio changed from 71.4 to 80.2 (95% CI 74.2−86.6) and in African men from 124.2 to 138.8 (95% CI 107.7−178.8). Conclusions: Ethnic variations deserve further study, including in White European origin subgroups and the Chinese. Extremely high rates in South Asian and African origin were not corroborated in Scotland. Linkage methods are practical in Europe.