Healthy lifestyle partly mediates the association between self-rated health and risk of overall and cause-specific mortality.

Abstract

Self-rated health status is a subjective but important indicator of an individual's perception of overall health. However, it remains unclear whether lifestyle may mediate or modify the association of self-rated health status with overall and cause-specific mortality. This prospective cohort analysis included 401,410 US adults from the National Institutes of Health-AARP Diet and Health Study. Self-rated health was categorized as "very good to excellent," "good," or "poor to fair." A healthy lifestyle was defined by a normal body mass index, never smoking, moderate alcohol consumption, adequate physical activity, and a higher diet quality score. Hazard ratios (HRs) and 95% confidence intervals (CIs) for overall and cause-specific mortality were estimated using multivariable-adjusted Cox models. During a median follow-up of 23.6 years, we ascertained 181,776 deaths. Compared with individuals reporting "very good to excellent" health, those reporting "poor to fair" health had an elevated risk of overall mortality (HR = 1.90, 95% CI: 1.87-1.93) as well as mortality from cardiovascular disease (CVD), heart disease, stroke, cancer, respiratory disease, diabetes, infection, and injuries and accidents (risk increment ranged from 24% to 361%). Mediation analysis showed that 5.1% to 33.6% of the observed associations were mediated by lifestyle. Self-rated health was more strongly associated with overall mortality than traditional risk factors except smoking. Compared with individuals reporting "very good to excellent" health who adhered to a healthier lifestyle, those reporting "poor to fair" health with a less healthy lifestyle experienced a significantly elevated risk of overall mortality and mortality from CVD, heart disease, cancer, and respiratory disease (relative excess risk due to interaction > 0). Poor self-rated health was significantly associated with higher risk of overall and cause-specific mortality, and these associations were partially mediated by lifestyle. A positive additive interaction between self-rated health and lifestyle was noted for overall mortality and for mortality from CVD, heart disease, cancer, and respiratory disease. These findings underscore the clinical importance of self-rated health and suggest that lifestyle modification may improve health and longevity, particularly among individuals with low or moderate self-rated health.