An assessment of intrinsic capacity among older Indian adults from the Longitudinal Ageing Study in India

Intrinsic capacity (IC), which comprises all physical and mental capacities of individuals, is a key component in the World Health Organization's healthy aging framework. A validated IC measure is lacking in India, the most populous country in the world. The aim of this study is to develop an IC measure in older Indian adults using 60,591 participants aged ≥45 years from the Longitudinal Ageing Study in India. Confirmatory factor analysis incorporated 14 items of cognitive, locomotor, psychological, sensory and vitality capacities in a bifactor structure and estimated IC scores (range 0-100). The mean score was 69.7 (95% confidence interval of 69.6 to 69.8) and varied across the 36 states and union territories (range 63.4-77.8). A higher IC score had protective associations with poor self-rated health and functioning limitations after adjusting for demographic factors, socioeconomic status and chronic conditions. The score provides a comprehensive indicator that can be implemented in future aging research and practices in India.