The Modifying Influence of Country Development on the Effect of Individual Educational Attainment on Self-Rated Health

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.The association between education and health has been widely researched. Individuals with higher educational attainment generally have lower rates of mortality and morbidity.1–4 Higher levels of education are also associated with decreased risk of poor health and functional limitations.5 It is apparent that, in addition to socioeconomic factors at the individual level, socioeconomic conditions at the population level play a role in the pathway to health. One common measure of a country’s human development is the Human Development Index (HDI). The HDI is intended to serve as a frame of reference for both social and economic development attained by a country’s citizens.The role of the political context of human development and health cannot be disregarded. Welfare regimes in which the financial emphasis, in terms of percentage of the gross domestic product, is on redistributive and full-employment policies are generally most successful in promoting a population’s health.6,7Although the effects of education and national development on health are well understood separately, little is known about the influence of national development on the relationship between education and health. This raises important questions about how education and increasing national development affect health in conjunction. This also has implications for educational inequalities in health. Does health inequality still play a prominent role in highly developed countries, or is it mainly a problem in less developed countries? Does investing in the national development of a country have a positive effect on educational inequalities in health? Although we do not yet have concrete answers to these questions, some work has been done. For instance, Rehkopf et al. compared the association of cardiovascular risk factors with education in Costa Rica and the United States and reported that the differential importance of education depends on the country context.8 The differences in mortality by educational attainment between the 2 countries could be attributable to the modifying effect development has on the relationship between education and health.We attempted to quantify the modifying influence of national development, as measured by the HDI, on the association of educational attainment with self-reported general health.