Decomposing the association of psychosocial wellbeing with all-cause mortality: the mediating role of physical health and lifestyle factors

Purpose: This study quantified the effect of 48 psychosocial constructs on all-cause mortality using data from 7,698 individuals in the U.S. Health and Retirement Study.

Methods: Latent class analysis was used to divide participants into mutually exclusive psychosocial wellbeing groups (good, average, or poor) which was subsequently considered as the exposure. Mediation analysis was then conducted to determine the direct effect of the psychosocial wellbeing groups and the indirect (mediating) effects of physical health (functional status and comorbid conditions) and lifestyle factors (physical activity, smoking, and alcohol consumption) on overall survival. We also created a composite health index measure representing the summative effect of the mediators.

Results: We observed a strong and statistically significant total effect (TE) between survival time and psychosocial wellbeing group (survival time ratio (SR) = 1.73, 95% confidence interval (CI):1.50,2.01 when comparing good to poor). Mediation analysis revealed that the direct effect via psychosocial wellbeing group accounted for more than half of the TE (SR = 1.46, 95% CI:1.27,1.67). The composite health index measure mediated 36.2% of the TE with the natural indirect effect SR of 1.18 (95% CI:1.13,1.22).

Conclusion: Our findings demonstrate the interconnectedness between psychosocial wellbeing and physical health and lifestyle factors on survival.