Domains contributing to disability in activities of daily living

The WHO International Classification of Functioning, Disability, and Health (ICF)-model describes disability in activities of daily living (ADL) as a multifactorial concept. According to this model, ADL disability is influenced by health conditions, body function and structures, environmental and personal factors, and participation. Current research on ADL disability often focuses on one domain and the contribution of multiple domains is not taken into account. The aim was to investigate which domains contribute to ADL disability.

Cross-sectional study.

General community.

A total of 537 middle-aged and older persons.

Health conditions included number of chronic diseases. Body function comprised Mini-Mental State Examination (MMSE), processing speed, memory, grip strength, physical performance score (PPS), physical activity, sensory problems, body mass index (BMI), intra-abdominal fat, and cholesterol/HDL ratio. Body structure included atherosclerosis and bone mineral density. Environmental factors comprised the degree of urbanization. Personal factors included age, sex, education, smoking, self-management abilities, quality of life, anxiety/panic disorders, and depressive symptoms. Associations between candidate predictors and ADL disability, measured on the Katz ADL-scale, were examined by multivariable adjusted logistic regression analysis. Nagelkerke R(2)-statistic was calculated to investigate the contribution of each domain to ADL disability.

Number of chronic diseases (domain health condition), MMSE, PPS, physical activity, BMI, intra-abdominal fat (domain body function), atherosclerosis (domain body structure) and sex, education, smoking, quality of life, and depressive symptoms (domain personal factors) were significant predictors of ADL disability. Fifty-seven percent of the variance in ADL disability was explained by the model. For each domain, the explained variance materially decreased after its exclusion, except for environmental factors.

The present study shows that multiple domains (ie, health condition, body function, body structure, and personal factors) contribute to current ADL disability.