Linear trend or graded association: an international study of objective and subjective socioeconomic inequalities in self-rated health

Abstract

Despite the well-documented socioeconomic inequalities in health, it is less known about how objective and subjective socioeconomic statuses (SES) are related to self-rated health (SRH) in an international context. Using data from the 2007 International Social Survey Program (ISSP) that included 33 countries across six continents (N = 40,049), we found that for objective SES, either education or income, or both were related to SRH as general linear trends (i.e., higher SES was associated with better SRH as a general trend) rather than graded associations (i.e., adjacent levels of SES were associated with SRH in a dose–response relationship). After controlling for subjective SES, the magnitude of the associations between objective SES and SRH reduced, whereas the associations between subjective SES and SRH remained strong in nearly all countries. Findings suggested that more rigorous analyses are needed to clearly describe the SES-health associations, and future international research should expand to include subjective measures of SES.