Ethnic differences between South Asians and White Caucasians in cardiovascular disease-related mortality in developed countries: a systematic literature review.

BACKGROUND: Cardiovascular disease is the leading cause of death worldwide, with significantly worse mortality-related outcomes in ethnic minorities in developed countries. A systematic literature review and meta-analysis of observational studies was conducted to investigate cardiovascular disease-related mortality inequalities between South Asian and White Caucasian ethnic groups. METHODS: Published studies on mortality between South Asians and Whites in developed countries were retrieved from MEDLINE, PubMed, Embase, Web of Science, and grey literature sources (inception-April 2021) and critically appraised using the Quality in Prognosis Studies tool. Bayesian random-effects meta-analyses were performed for both primary and secondary outcomes. Heterogeneity was determined using the I2 statistic. RESULTS: Of the 9879 studies screened originally, 41 were deemed eligible. A further 3 studies were included via the later search. Of these, 15 reported cardiovascular disease-related mortality, 23 reported all-cause mortality, and 6 reported both. The meta-analysis results showed that South Asians had a significantly increased risk of cardiovascular disease mortality compared to Whites (risk ratio = 1.32; 95% credible interval = 1.14 to 1.54) and a decreased risk of all-cause mortality (risk ratio = 0.95; 95% credible interval = 0.83 to 1.12). DISCUSSION: South Asians had statistically significantly higher odds of cardiovascular disease-related mortality compared to Whites, but not for all-cause mortality. Risk of bias was a serious concern mainly due to a lack of confounders being reported. SYSTEMATIC REVIEW REGISTRATION: PROSPERO: CRD42021240865.

Ethnic differences between South Asians and white Caucasians in cardiovascular disease-related mortality in developed countries: a systematic literature review protocol.

INTRODUCTION: Cardiovascular disease (CVD) is the leading cause of death worldwide, with significantly worse CVD outcomes in ethnic minorities in developed countries, especially South Asians, compared with the prevailing white ethnic group. This protocol outlines the process for conducting a systematic literature review to investigate the CVD outcome inequalities between South Asian and white Caucasian ethnic groups. METHODS: Studies that compared the South Asian ethnic minority with the predominant white ethnicity in developed countries with CVD will be included from inception to 22 April 2021. We will search MEDLINE, Embase, Web of Science and grey literature to find all relevant peer-reviewed articles, reports and online theses. Articles will be screened using inclusion/exclusion criteria applied first at the title and abstract level, and then full texts, both by two independent reviewers. Articles kept in the review will undergo a risk of bias assessment using the Quality In Prognosis Studies tool and data will be extracted. Random-effects meta-analysis and heterogeneity tests will be undertaken, and tests for publication bias, outlying highly-influential observations. If insufficient data is founded or studies are highly heterogeneous, a narrative synthesis will be conducted. ETHICS: Formal ethical approval is not required for this review. DISSEMINATION: The results and findings of this systematic literature review will be disseminated through peer-reviewed publications and reports. PROSPERO REGISTRATION NUMBER: CRD42021240865.