Socio-demographic and lifestyle factors associated with intrinsic capacity among older adults: evidence from India

Background Since the traditional models missed the possibility of formulating personalised programs centred on a person's priorities and values, it was a pressing priority to shift from traditional disease-centred to a function-based approach of healthy ageing, which is defined as 'the process of developing and maintaining the functional ability that enables well-being in older age'. The present study aimed to assess the prevalence of high intrinsic capacity (IC) of older adults and to examine the socio-demographic and lifestyle factors associated with IC among older adults in India. Methods The study utilises the individual-level data from the first wave of the Longitudinal Aging Study in India (LASI) conducted during 2017-18. The total sample size for the present study was 24,136 older adults (11,871 males and 12,265 females) aged 60 years and above. Descriptive statistics, along with bivariate analysis, was employed to present the preliminary results. Additionally, multivariable linear and logistic regression analyses were conducted to find out the association of socio-demographic and lifestyle factors with IC and its components. Results The mean IC score was found to be 7.37 (SD = 1.6) in this study. A proportion of 24.56% of older adults was observed to be in the higher IC category. Increasing age was negatively associated with high IC for older men and women. Older people who smoke tobacco (beta = -0.23; CI: -0.32--0.13) and chew tobacco (beta = -0.11; CI: -0.18--0.03) were less likely to experience high IC compared to their respective counterparts. Older adults who reported episodic alcohol drinking were less likely to have high IC (beta = -0.20; CI:-0.32--0.07). The engagement in moderate physical activity (beta = 0.12; CI:0.01-0.23), vigorous physical activity (beta = 0.12; CI:0.05-0.20) and yoga-related activity (beta = 0.18; CI:0.09-0.26) were significantly positively associated with high IC. Among the five domains of IC, education was significantly associated with higher capacity in each domain, and increasing age was found to be a significant predictor of lower capacity in each IC domain except locomotion. Older men and women engaged in vigorous physical activity had 35 and 19% significantly higher odds of high capacity in sensory (aOR = 1.35; CI: 1.12-1.62) and psychological (aOR = 1.19; CI: 1.06-1.34) domains, respectively. Conclusions The study revealed that lifestyle behaviours including tobacco use, episodic alcohol drinking and physical activity are strongly associated with IC among older adults in India. The findings suggest that healthy lifestyle behaviours should be encouraged among older adults as an effort to improve their IC, which is the key determinant of functional ability and quality of life in later years of life.