Health and Economic Consequences of Depressive Transitions in Prefrail Older Adults

Abstract Background Frailty contributes to disability and rising healthcare costs in aging populations. The pre-frail stage offers a key opportunity for low-cost prevention. As a modifiable risk factor, depression may influence progression to frailty or recovery. Methods We used data from two cohorts: the China Health and Retirement Longitudinal Study (CHARLS, n = 2806) and the US Health and Retirement Study (HRS, n = 2760). We categorized depressive status transitions as stable, onset, remission, or persistent across two waves. Prefrail individuals were tracked for transitions to frailty or robustness. Fine-Gray competing risk models estimated subdistribution hazard ratios (sHRs), adjusting for demographic and health factors. Analyses were stratified by sex. We also used Markov modeling to simulate frailty trajectories over a 5-year period and estimate group-specific healthcare costs. Economic outcomes included average cost per group and return on investment under hypothetical intervention scenarios. Results Depression onset was associated with increased frailty risk in both cohorts (CHARLS: sHR=1.58, 95%CI: 1.27-1.97; HRS: sHR=1.57, 95%CI: 1.28-1.93), and with reduced robust recovery in CHARLS (sHR=0.77, 95%CI: 0.63-0.94). Depression remission reduced frailty risk (CHARLS: sHR=0.72, 95%CI: 0.59-0.87; HRS: sHR=0.78, 95%CI: 0.63-0.95) and improved recovery only in CHARLS (sHR=1.37, 95%CI: 1.10-1.71). In sex-stratified analyses, associations were stronger among females. Markov simulations indicated that enhancing transitions related to depression could lead to notable savings in per-person healthcare costs over a five-year period. Conclusions Depressive transitions shape late-life health and cost outcomes. Addressing depression in prefrail adults may enhance recovery and reduce long-term care costs. Mental health investment is a cost-effective strategy to support healthy aging. Key messages • Transitions in depressive symptoms may contribute to differences in frailty trajectories, with stronger associations observed among women in this study. • Early mental health interventions in prefrail adults are both clinically effective and economically justified.