Intrinsic capacity and survival among older adults in India: LASI-DAD study (wave 1 and wave 2).

Abstract

With increasing longevity, the focus of healthcare for older adults is shifting from a disease-centric model to a more holistic view of functional capacity. This study investigates the relationship between intrinsic capacity (IC)-a measure of combined physical and mental abilities-and survival among older adults in India. We analysed data from 4096 community-dwelling individuals aged 60 and older who participated in the Longitudinal Aging Study in India-Diagnostic Assessment of Dementia (LASI-DAD). IC was evaluated across six domains: cognition, mood, nutrition, locomotion, vision, and hearing. An overall IC score was created by aggregating the z-scores from these domains. Cox Model was used to determine if IC was a predictor of mortality, adjusting for confounding factors. During the follow-up period, 951 participants (23.2%) died. A higher IC score was associated with a lower risk of death (Hazard Ratio (HR): 0.89; 95% CI: 0.86-0.91). The risk of mortality increased progressively with the number of impaired intrinsic capacity domains: participants with one impaired domain had a HR of 1.48 (95%CI 1.26-1.75); two impaired domains, HR: 2.10 (95%CI 1.67-2.65); three impaired domains, HR: 1.71 (95%CI 1.14-2.57); and four impaired domains, HR: 3.15 (95%CI 1.53-6.46). Of the six domains, cognition, nutrition, and locomotion were identified as the strongest predictors of survival. Vision impairment did not show a independent association with mortality. Older adults in India with higher overall intrinsic capacity-particularly better cognition, good nutrition, and better locomotor capacity-had a lower risk of death. These findings highlight the importance of looking at functional abilities, not just diseases, when planning health care and interventions for ageing populations. LASI-DAD is funded by the National Institute on Aging, the National Institutes of Health (R01 AG051125, U01AG064948).