Variations between world regions in individual health: a multilevel analysis of the role of socio-economic factors

Background: Living in a particular region might affect health. We aimed to assess variations between regions in individual health. The role of socio-economic factors in the associations was also investigated. Methods: World Health Survey data were analysed on 220 487 individuals. Main outcomes included self-reported health, health complaints and disability. The main predictor variable was a modified regional classification of countries. Multilevel logistic regression was used to assess associations between individual health and regions, while accounting for individual and country-level socio-economic factors, notably occupation, education, national income and female literacy. Results: Individual health varied significantly between regions. For instance, compared with Western Europeans, Southern Asians and Western Africans reported poorer health, the odds ratios (ORs) being 2.05 [95% confidence interval (CI) 1.31-3.23] and 1.88 (95% CI 1.26-2.81), respectively. Accounting for socio-economic factors attenuated or, in a few cases, reversed the associations. For example, the OR for Southern Asia and Western Africa respectively became 0.94 (95% CI 0.37-2.37) and 0.77 (95% CI 0.26-2.25). Individuals from Central Europe and the Former Soviet Union were the most likely to report poor health, OR 1.92 (95% CI 1.07-3.44) and OR 4.17 (95% CI 1.91-9.10) respectively. Overall, men were less likely than women to report poor health. Conclusion: Substantial regional variations in individual health exist, only partly explained by socio-economic factors. Additional policy and health research are needed to investigate Central Europe and Former Soviet Union rates that consistently lag behind Latin America, Asia and Africa