Effects of education and income on cardiovascular outcomes: a systematic review and meta-analysis

Objective: Previous studies have reported discrepancy effects of education and income on cardiovascular diseases. This systematic review and meta-analysis was therefore conducted which aimed to summarize effects of education and income on cardiovascular diseases. Methods: Studies were identified from Medline and Scopus until July 2016. Cohorts were eligible if they assessed associations between education/income and cardiovascular diseases, had at least one outcome including coronary artery diseases, cardiovascular events, strokes and cardiovascular deaths. A multivariate meta-analysis was applied to pool risk effects of these social determinants. Results: Among 72 included cohorts, 39, 19, and 14 were studied in Europe, USA, and Asia. Pooled risk ratios of low and medium versus high education were 1.36 (95% confidence interval: 1.11-1.66) and 1.21 (1.06-1.40) for coronary artery diseases, 1.50 (1.17-1.92) and 1.27 (1.09-1.48) for cardiovascular events, 1.23 (1.06-1.43) and 1.17 (1.01-1.35) for strokes, and 1.39 (1.26-1.54) and 1.21 (1.12-1.30) for cardiovascular deaths. The effects of education on all cardiovascular diseases were still present in US and Europe settings, except in Asia this was present only for cardiovascular deaths. Effects of low and medium income versus high on these corresponding cardiovascular diseases were 1.49 (1.16-1.91) and 1.27 (1.10-1.47) for coronary artery diseases, 1.17 (0.96-1.44) and 1.05 (0.98-1.13) for cardiovascular events, 1.30 (0.99-1.72) and 1.24 (1.00-1.53) for strokes, and 1.76 (1.45-2.14) and 1.34 (1.17-1.54) for cardiovascular deaths. Conclusion: Social determinants are risk factors of cardiovascular diseases in developed countries, although high heterogeneity in pooling. Data in Asia countries are still needed to update pooling.