Prevalence of behavioural cardiovascular disease risk factors in UK-born ethnic minorities: a systematic review for public health guidance

Background Some behavioural cardiovascular risk factors are known to be high in ethnic minority groups in the UK. In 2011, about half of all Indians, Pakistanis, Bangladeshis, and black Caribbeans living in the UK were born in the UK; however, little is known about whether the prevalence of cardiovascular risk factors differs between overseas-born and UK-born ethnic minorities. We aimed to investigate the prevalence of behavioural cardiovascular risk factors in UK-born ethnic groups. A common explanation for ethnic differences in health behaviours is socioeconomic factors; therefore, we also looked to see if the reasons behind any differences within and between UK-born ethnic groups had been explored. A main aim was also to assess the quality of reports on this topic. Methods We searched Medline, Embase, and PubMed for observational quantitative manuscripts. Selected manuscripts were those published between 1990 and 2012 and reporting on UK-born adult populations of black Caribbeans, black Africans, Indians, Pakistanis, or Bangladeshis, either alone or in comparison with another subgroup of the population. Manuscripts had to report on the prevalence of dietary factors, alcohol use, tobacco use, physical activity, or obesity. The titles and abstracts of manuscripts were screened and then the selected manuscripts were read in full. References of all manuscripts read in full were searched for further manuscripts. Exclusion of reports of poor quality is conventional, which might introduce biases into the results. Because one of the aims of this review was to assess the quality of the manuscripts, manuscripts of all quality were retained in the review and assessed using a quality appraisal instrument from the report on the methods used to develop the National Institute for Health and Care Excellence Public Health guidance. Quality assessors were not masked. Findings 124 manuscripts were identified through the search strategy after duplicates were removed. 23 manuscripts were read in full and ten studies were included in the review. The included manuscripts showed some evidence of a different prevalence of behavioural cardiovascular risk factors in the UK-born ethnic groups when compared with migrants and the white British ethnic group (appendix). In Indian women, the prevalence of smoking was 3·3% in the first generation but 10·2% in the second generation. Physical activity levels were higher in the second generation for all ethnic groups included; however, levels were still lower than in the general population. Compared with the general population, one manuscript suggested higher intakes of fried foods in UK-born ethnic minority participants (33·4% of UK-born Pakistanis eating fried food three or more times a week compared with 18·4% from the white group), but lower levels of alcohol intake and tobacco use. Some manuscripts attempted to minimise their risk of bias; however, underpowered samples and failure to adjust for important confounding variables limited the generalisability of their results. Because most manuscripts did not include socioeconomic factors in their regression models, we could not assess the contribution of this to differences in risk factors. Interpretation This review revealed some evidence of a different profile of cardiovascular risk factors in UK-born ethnic minorities, as compared with the migrant generation, although explanations for these differences are inadequate. Research with theoretical approaches and adequate sample sizes is needed to firmly establish any differences in prevalence between generations of ethnic minorities. As far as we are aware, this is the first manuscript to review and assess the quality of studies that examine the prevalence of cardiovascular behavioural risk factors in UK-born ethnic minorities. A limitation of this study is that the title and abstract screening was done by one person, although the final selection of manuscripts was agreed by all authors. Funding The main authors are funded by the British Heart Foundation.