Declined intrinsic capacity predicts long-term mortality in Chinese older adults: Beijing Longitudinal Study of Aging

Background

Intrinsic capacity reflects an individual's functions and capacities across their lifetime. There are few studies on whether the level of intrinsic capacity can predict long-term mortality in Chinese populations.

Objective

To explore the effects of intrinsic capacity on long-term outcomes in older Chinese adults.

Methods

Data were obtained from the Beijing Longitudinal Study of Aging. Overall, 1699 community-dwelling adults aged ≥60 years were included and followed up for 8 years. Intrinsic capacity was determined according to the World Health Organization definition. The predictive ability for adverse outcomes was assessed using the age- and sex-adjusted Cox proportional hazards model.

Results

A decline in intrinsic capacity domains was observed in 729 (42.9 %) participants. Declines in the mobility, cognition, vitality, sensory and psychology domains were observed in 21.8 %, 15.1 %, 11.4 %, 9.10 %, and 14.2 % of the participants, respectively. Low intrinsic capacity was associated with worse physical performance, frailty, social frailty, chronic diseases, fracture, and falls. A greater decline in intrinsic capacity predicted an elevated 8-year mortality rate (decline in overall intrinsic capacity hazard ratio 2.91, 95 % confidence interval 2.44–3.47, P < 0.001; decline in one domain hazard ratio 2.11, 95 % confidence interval 1.71–2.61, P < 0.001; decline in two domains hazard ratio 3.54, 95 % confidence interval 2.81–4.45, P < 0.001; decline in three or more domains hazard ratio 5.30, 95 % confidence interval 4.09–6.87, P < 0.001); adjusted models did not affect prediction performance. Among the five domains of intrinsic capacity, cognition was the strongest predictor of mortality (hazard ratio 3.17, 95 % confidence interval 2.63–3.81, P < 0.001).

Conclusions

Intrinsic capacity is useful in identifying older adults at higher risk of adverse outcomes, presenting significant implications for healthcare policies in China.