Self-rated Health and Mortality due to Kidney Diseases: Racial Differences in the United States.

Background: Although the role of self-rated health (SRH) on all-cause mortality is known, we still do not know whether SRH predicts death due to specific causes (e.g., kidney disease). The current study aimed to compare Blacks and Whites on the association between SRH and mortality due to kidney diseases. A nationally representative sample of adults in the United States was used to provide generalizable results to the United States population.

Materials and Methods: The Americans' Changing Lives study is a nationally representative cohort, conducted from 1986-2011. The study followed 3361 Blacks ( n = 1156) and Whites ( n = 2205) for up to 25 years. The outcome was time to death due to kidney diseases, derived from death certificates and the National Death Index. Cox proportional hazards models were used to test whether race and baseline SRH interact on mortality due to kidney diseases.

Results: In the pooled sample, poor SRH (odds ratio [OR] = 2.29, 95% confidence interval [CI] = 1.24-4.24) was associated with an increased risk of death due to kidney diseases over the follow-up period. Baseline SRH also showed a significant interaction with race on the outcome (OR = 0.49, 95% CI = 0.25-0.96), suggesting a stronger effect of SRH on deaths due to kidney diseases for Whites compared to Blacks. In race-specific models, poor SRH at baseline increased risk of death due to kidney diseases among Whites (OR = 2.23, 95% CI = 1.14-4.34) but not Blacks (OR = 1.14, 95% CI = 0.54-2.41).

Conclusions: Blacks and Whites differ regarding the predictive role of baseline SRH on death due to kidney diseases over time. Factors such as SRH better predict risk of mortality for Whites than for Blacks.