Mortality from all causes and circulatory disease by country of birth in England and Wales 2001-2003

Large-scale epidemiological data on cardiovascular diseases and diabetes in migrant and ethnic minority groups in Europe

BACKGROUND

Data on differences by ethnicity in cardiovascular diseases (CVDs) and diabetes, reflecting the influence of diverse cultural, social and religious factors, are important to providing clues to disease aetiology and directing public health interventions and health care resources.

METHODS

Through a network of European public health researchers and searches of bibliographic databases and internet sites, we determined the availability and characteristics of ethnically relevant data on mortality and morbidity from coronary heart disease (CHD), stroke and diabetes, in current European Union countries; data from the four countries comprising the UK were assessed separately.

RESULTS

In total, 25 countries had one or more relevant data sets (72 in total); however, two-thirds (n = 47) of the data sources came from only eight Nordic and Western European countries. For several countries, no data could be identified. Ethnically relevant, national death registers were available in 24 countries. Country of birth was the most common indicator of ethnicity. Data on CHD, stroke and diabetes morbidity among migrant and ethnic minority populations are currently scarce; both between and within countries, there are important differences in how ethnicity as well as disease outcomes are defined and measured which limits data comparability.

CONCLUSION

Reliable routine data are key to evidence-based public health policies at both national and EU level. EU countries have a relatively weak base for assessing needs and planning health care interventions for its migrant and ethnic minority populations. The lack of ethnically relevant data on CVD and diabetes across the EU needs to be addressed urgently.

Ethnic and gender differences in physical activity levels among 9-10-year-old children of white European, South Asian and African-Caribbean origin: the Child Heart Health Study in England (CHASE Study)

BACKGROUND

Ethnic differences in physical activity in children in the UK have not been accurately assessed. We made objective measurements of physical activity in 9-10-year-old British children of South Asian, black African-Caribbean and white European origin.

METHODS

Cross-sectional study of urban primary school children (2006-07). Actigraph-GT1M activity monitors were worn by 2071 children during waking hours on at least 1 full day. Ethnic differences in mean daily activity [counts, counts per minute of registered time (CPM) and steps] were adjusted for age, gender, day of week and month. Multilevel modelling allowed for repeated days within individual and clustering within school.

RESULTS

In white Europeans, mean daily counts, CPM and mean daily steps were 394,785, 498 and 10,220, respectively. South Asian and black Caribbean children recorded more registered time per day than white Europeans (34 and 36 min, respectively). Compared with white Europeans, South Asians recorded 18 789 fewer counts [95% confidence interval (CI) 6390-31 187], 41 fewer CPM 95% CI 26-57) and 905 fewer steps (95% CI 624-1187). Black African-Caribbeans recorded 25 359 more counts (95% CI 14 273-36 445), and similar CPM, but fewer steps than white Europeans. Girls recorded less activity than boys in all ethnic groups, with 74 782 fewer counts (95% CI 66 665-82 899), 84 fewer CPM (95% CI 74-95) and 1484 fewer steps (95% CI 1301-1668).

CONCLUSION

British South Asian children have lower objectively measured physical activity levels than European whites and black African-Caribbeans.

Comparison of elderly suicide rates among migrants in England and Wales with their country of origin

BACKGROUND

The black and minority ethnic (BME) elderly population size in England and Wales has progressively increased over the last three decades. Only two studies, both well over a decade old, have compared suicide rates in BME groups in England and Wales with those in their country of origin.

METHODS

A study comparing suicide rates among elderly migrants in England and Wales and in their country of origin using the latest available mortality data from the Office of National Statistics and the World Health Organization was conducted.

RESULTS

There were wide variations in standardised mortality ratios for elderly suicides among migrants from different countries compared with those born in England and Wales and in their country of origin. There was convergence towards elderly suicide rates for England and Wales in some migrant groups in males in the age-bands 65-74 years and 75 + years, and in females in the age-band 75 + years. However, males aged 75 + years from most migrant groups had higher rates than those born in England and Wales.

CONCLUSION

A more detailed analysis of suicide of older people from migrant groups is required to determine vulnerability and protective influences.

Ethnic differences in retinal microvascular structure

AIMS/HYPOTHESIS

People of African origin have increased risk of stroke and retinal microvascular disease compared with populations of European origin. We compared quantitative measures of retinal microvasculature in British white Europeans and African Caribbeans.

METHODS

Population-based study of 215 (45% male) British African-Caribbean migrants and 323 (48% male) white Europeans aged 40-69 years. Digitised retinal images were analysed using a validated semi-automated system.

RESULTS

Arteriolar optimality deviation, an indicator of endothelial dysfunction, was greater in African Caribbeans (age- and sex-adjusted means [95% CIs]: 0.06 [0.05-0.06] vs 0.04 [0.04-0.05], p = 0.004); this was unexplained by conventional risk factors. Arteriolar diameters were narrower in African Caribbeans (age- and sex-adjusted means [95% CIs]: 18.4 [18.1-18.6] vs 17.9 [17.6-18.2], p = 0.011). These ethnic differences in diameters were attenuated on adjustment for systolic BP (SBP) (adjusted means: 18.2 vs 18.1, p = 0.31). However, there was a significant interaction (p = 0.011) between diabetes and SBP, such that SBP was strongly associated with arteriolar diameter in people without diabetes, but not in those with diabetes (adjusted beta-coefficients for SBP: Europeans: -0.42, p = 0.002 vs 0.17, p = 0.69, African Caribbeans: -0.35, p = 0.023 vs 0.01, p = 0.96). Other measures of retinal vasculature did not differ by ethnicity.

CONCLUSIONS/INTERPRETATION

British African Caribbeans appear to have poorer retinal arteriolar endothelial function than white Europeans. Higher BPs explained the narrower arterioles in African Caribbeans; however, patterns of association between arteriolar narrowing and BP suggest the possibility that cerebral autoregulation and/or remodelling might be adversely affected by diabetes in both ethnic groups.

Hypertension in Mexico and among Mexican Americans: prevalence and treatment patterns

Increased social and economic integration across the US-Mexican borders has led to important new developments in public health. Lower levels of cardiovascular mortality have been observed among Mexican Americans (MAs) although few direct comparisons have been undertaken with Mexico. Using survey data in the respective countries we examined blood pressure (BP) levels, hypertension prevalence and patterns of awareness, treatment and control in Mexico and among MAs. A national representative sample of the adult population from Mexico collected in 2000 (N=49 294), and data on 8688 MA participants in the 1999-2004 National Health and Nutrition Examination survey from the United States were available for analysis. US-born MAs and those born in Mexico were analysed separately in the US data. Lack of direct standardization of methods between surveys necessitated statistical adjustment of BP values. Analyses were based on persons aged 25-64 in each country. Sex- and age-adjusted mean systolic/diastolic BPs were 122/80, 119/71 and 120/73 in Mexicans, immigrant MAs and US-born MAs, respectively. The prevalences of hypertension (BP > or = 140/90 or treatment) were 33, 17 and 22%. Hypertension control rates were 3.7, 32.1 and 37.9%, in the same groups. Awareness and treatment rates were 25 and 13% in Mexico and 54 and 46% among MAs in the United States, respectively. Hypertension appears to be more common in Mexico than among Mexican immigrants to the United States. Despite relatively low access to health insurance in the United States, hypertension control increased over the course of this migration.

Vascular risk factors in South Asians

South Asians originate from the Indian sub-continent (India, Pakistan, Bangladesh, Sri Lanka and Nepal) and represent one fifth of the world's population. Several studies suggested that South Asians have an increased risk of developing coronary heart disease (CHD) when compared with European populations. We review the role of traditional and emerging risk factors in the increased CHD risk in South Asians. The high prevalence of insulin resistance and type 2 diabetes mellitus in South Asians may be a major cause for their elevated vascular risk. However, other established and emerging risk factors are also overrepresented in South Asians. Large-scale prospective studies could determine the relative contribution of established and emerging vascular risk factors in South Asians. There is an urgent need for trials in South Asians that will evaluate clinical outcomes following treatment of these risk factors.

Trends for coronary heart disease and stroke mortality among migrants in England and Wales, 1979-2003: slow declines notable for some groups

Objective:

To examine trends in coronary heart disease and stroke mortality in migrants to England and Wales.

Design:

Cross-sectional.

Outcome measures:

Age-standardised and sex-specific death rates and rate ratios 1979–83, 1989–93 and 1999–2003.

Results:

Coronary mortality fell among migrants, more so in the second decade than the first. Rate ratios for coronary mortality remained higher for men and women from Scotland, Northern Ireland, Republic of Ireland and South Asia, and lower for men from Jamaica, other Caribbean countries, West Africa, Italy and Spain. Rate ratios increased for men from Jamaica (1979–83: 0.45, 0.40 to 0.50; 1999–2003: 0.81, 0.73 to 0.90), Pakistan (1979–83: 1.14, 1.04 to 1.25; 1999–2003: 1.93, 1.81 to 2.06), Bangladesh (1979–83: 1.36, 1.15 to 1.60; 1999–2003: 2.11, 1.90 to 2.34), Republic of Ireland (1979–1983: 1.18, 1.15 to 1.21; 1999–2003: 1.45, 1.39 to 1.52) and Poland (1979–83: 1.17, 1.09 to 1.25; 1999–2003: 1.97, 1.57 to 2.47), and for women from Jamaica (1979–83: 0.63, 0.52 to 0.77; 1999–2003: 1.23, 1.06 to 1.42) and Pakistan (1979–83: 1.14, 0.88 to 1.47; 1999–2003: 2.45, 2.19 to 2.74), owing to smaller declines in death rates than those born in England and Wales. Rate ratios for stroke mortality remained higher for migrants. As a result of smaller declines, rate ratios increased for men from Pakistan (1979–1983: 0.99, 0.76 to 1.29; 1999–2003: 1.58, 1.35 to 1.85), Scotland (1979–1983: 1.11, 1.04 to 1.19; 1999–2003: 1.30, 1.19 to 1.42) and Republic of Ireland (1979–1983: 1.27, 1.19 to 1.36; 1999–2003: 1.67, 1.52 to 1.84).

Conclusion:

For groups with higher mortality than people born in England and Wales, mortality remained higher. Smaller declines led to increasing disparities for some groups and to excess coronary mortality for women from Jamaica. Maximising the coverage of prevention and treatment programmes is critical.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.