Psychological frailty index and incident cardiovascular disease risk in older adults: a prospective cohort study from CHARLS

Background Psychological frailty is an emerging multidimensional construct reflecting psychological, cognitive, and functional vulnerability in later life. Its prospective association with incident CVD and its incremental predictive value beyond conventional cardiovascular risk factors remain unclear. We examined whether PFI was associated with incident CVD among older adults in CHARLS. Methods This prospective cohort study used CHARLS Wave 4 as baseline and Wave 5 for outcome assessment. The primary cohort included adults aged ≥ 65 years who were free of CVD at baseline and had complete 15-item PFI data. PFI was analysed continuously, as binary psychological frailty, and by three-category classification. Modified Poisson regression with robust standard errors estimated RRs and 95% CIs. Domain-specific associations, cumulative domain burden, CVD subtypes, subgroup consistency, sensitivity analyses, and incremental predictive performance were evaluated. Results Among 1,623 older adults, 174 developed incident CVD. Incident CVD occurred in 8.4%, 11.6%, and 17.9% of participants with robust status, pre-psychological frailty, and psychological frailty, respectively. In the fully adjusted model, each 0.1-point increase in PFI was associated with higher incident CVD risk (RR 1.27, 95% CI 1.14–1.41; P < 0.001). Psychological frailty was also associated with increased risk compared with non-frailty (RR 1.62, 95% CI 1.20–2.20; P = 0.002) and with robust status (RR 1.86, 95% CI 1.29–2.66; P < 0.001). Among PFI domains, physical vulnerability showed the strongest independent association with incident CVD (RR per 0.1-point increase 1.18, 95% CI 1.10–1.26; P < 0.001). Each additional elevated PFI domain was associated with higher CVD risk (RR 1.37, 95% CI 1.14–1.64; P < 0.001). Associations were more consistent for incident heart disease than stroke and were robust in sensitivity analyses. Adding PFI to conventional risk factors modestly improved predictive performance, with AUC increasing from 0.628 to 0.657, IDI of 0.013, and continuous NRI of 0.282. Conclusions Higher PFI was prospectively associated with increased incident CVD risk in older adults, with the observed association reflecting multidimensional vulnerability and physical vulnerability showing the strongest independent domain-specific association. Adding PFI to conventional risk factors resulted in modest improvement in predictive performance. PFI may provide complementary information on cardiovascular vulnerability, although further external validation is required before its use for cardiovascular risk stratification. Clinical trial number Not applicable.