Socioeconomic variation in the magnitude of the association between self-rated health and mortality

Abstract

Purpose: To assess socioeconomic variation in the association between self-rated health (SRH) and mortality and to determine whether socioeconomic inequalities in SRH and socioeconomic inequalities in mortality differ in magnitude.

Methods: We used data from a cohort of Spanish people 60 years of age and older with an 8-year follow-up of mortality. The association between SRH at baseline and mortality was estimated by the age-adjusted relative risk of mortality in people with low, medium, and high education. The measures of health inequalities were the prevalence ratio of poor SRH and the age-adjusted relative risk of mortality according to educational level. The validity of SRH to reflect life-threatening and non-life-threatening health conditions was summarized with the likelihood ratio for poor SRH in each educational category.

Results: The relative risk of mortality according to SRH in subjects with high and low education was 3.24 and 1.62 in men and 2.25 and 1.50 in women, respectively. Inequalities in poor self-rated health were larger than inequalities in mortality: -1.63 versus 1.07 in men and 1.45 versus 1.30 in women. The highest likelihood ratio for SRH was seen in persons with high education in the case of life-threatening conditions, and for those with low education, in the case of non-life-threatening conditions.

Conclusions: Socioeconomic variation in the validity of SRH to reflect life-threatening and non-life-threatening conditions could explain the greater ability of SRH to predict mortality in persons with high education and why inequalities in poor SRH are larger than inequalities in mortality.