Identifying factors associated with changes in physical functioning in an older population

Aim: The present study evaluated the association between changes in physical functioning and a variety of factors in an older population in Taiwan. Methods: The data of 907 participants were derived from a three-wave cohort study of aging, the Functioning and Aging Study in Taipei, with a study period from 2005 to 2009. Functional status was assessed using activities of daily living, instrumental activities of daily living and mobility tasks, and classified as being normal, with mild disability, moderate disability, and severe disability. All potential factors were allocated into five groups including demography, chronic diseases, geriatric conditions, lifestyle and physical assessments. Generalized estimating equations and generalized linear mixed-effects models were used to identify factors responsible for changes in physical functioning across different waves of data. Results: The proportion of elderly participants with normal function decreased with time throughout the study period. The results of Generalized estimating equations and mixed effects models showed nearly identical sets of factors. These included age, living arrangements, social support, self-rated health, stroke, diabetes, Parkinson's disease, osteoporosis, depression, cognition, vision, history of fracture and falls, incontinence of urine and feces, physical activity, body mass index, and short physical performance battery. Conclusions: Older persons with stroke, Parkinson's disease, diabetes, osteoporosis, geriatric conditions and poor short physical performance battery score should be considered as the target of prevention against functional decline. Those not living with spouses, with poor self-rated health, with low social support, being underweight or obese and with a sedentary lifestyle might also require major attention.