Limitations in physical functioning among older people as a predictor of subsequent disability in instrumental activities of daily living.

BACKGROUND: physical functioning describes the underlying abilities that make activities necessary for independent living in the community possible.
OBJECTIVE: to test self-reported and objective measures of physical functioning in predicting subsequent disability in cooking, shopping and housework.
DESIGN: we used data from the first and second waves of the Survey of Health, Ageing and Retirement in Europe. The respondents were asked about physical functioning (climbing, pulling/pushing, stooping/crouching/kneeling, lifting/carrying and reaching/extending were comparable) and they had their grip strength and walking speed measured. PARTICIPANTS: men and women aged 65 years or over who reported no disability in cooking, shopping and housework at baseline were included in the analysis. There were 6,841 individuals for whom data on disability status at follow-up were available.
METHODS: Poisson regression was used to calculate relative risks for the associations between self-reported and objective measures of physical functioning with disability at 2 years, adjusting for age, gender, educational level, cognitive function and chronic conditions.
RESULTS: those with limitations in physical functioning at baseline more frequently reported subsequent disability. Walking ability was most strongly associated with disability; climbing, pulling/pushing, lifting/carrying and reaching/extending were comparable (picking was non-significant). Similar results were obtained with grip strength and walking speed.
CONCLUSIONS: both self-reports and objective measures capture information on the functional ability of older people that can be used to predict disability onset. Objective measures offer little to the development of intervention strategies, whereas self-reports provide some insight into the demands of the environment, being more amenable to interventions.