How Much Do Preventive Health Behaviors Explain Education- and Income-related Inequalities in Health? Results of Oaxaca-Blinder Decomposition Analysis

Purpose: Five health practices are recognized to be essential for the prevention of chronic disease, viz. avoiding smoking, drinking in moderation, healthy diet, regular physical activity, and adequate sleep. However, how much of these behaviors contribute to socioeconomic disparities in health continues to be debated-some claim "hardly any," while others say "nearly all."

Methods: The data were from the NHANES 2015-16. Selected outcomes were self-rated health, hypertension, cardiovascular disease, and diabetes. Socioeconomic status was measured by education and household income. We implemented Oaxaca-Blinder decomposition to examine the extent to which socioeconomic inequalities in health could be explained by socioeconomic differences in adherence to health practices.

Results: 55%-90% of education-based inequalities in hypertension (89%), cardiovascular diseases (56%), and diabetes (75%) could be explained by health practices-especially current smoking and overweight. By contrast, most income-related inequalities in health outcomes could not be explained by health practices.

Conclusions: How much heath practices can account for socioeconomic inequalities in health depends on the indicator of socioeconomic status. Educational disparities in health is explained by the higher prevalence of smoking and overweight in educationally disadvantaged groups. However, income-related gaps in health may require further consideration besides lifestyle modification.