Objectives: We investigated how much the Human Development Index (HDI), a global measure of development, modifies the effect of education on self-reported health.
Methods: We analyzed cross-sectional World Health Survey data on 217,642 individuals from 49 countries, collected in 2002 to 2005, with random-intercept multilevel linear regression models.
Results: We observed greater positive associations between educational levels and self-reported good health with increasing HDI. The magnitude of this effect modification of the education-health relation tended to increase with educational attainment. For example, before adjustment for effect modification, at comparable HDI, on average, finishing primary school was associated with better general health (b = 1.49; 95% confidence interval [CI] = 1.18, 1.80). With adjustment for effect modification by HDI, the impact became 4.63 (95% CI = 3.63, 5.62) for every 0.1 increase in HDI. Among those who completed high school, these associations were, respectively, 5.59 (95% CI = 5.20, 5.98) and 9.95 (95% CI = 8.89, 11.00).
Conclusions: The health benefits of educational attainment are greater in countries with greater human development. Health inequalities attributable to education are, therefore, larger in more developed countries.