The responsibilities for the care of a significant portion of the population with an intellectual disability (ID) were recently transferred from the government to the municipalities. It is therefore important that policymakers and care professionals know how much support this population needs in their daily life. Therefore, this study focuses on the decline in daily functioning of older adults with ID (≥50 years, n = 703) over 3 years, and if daily functioning is a predictor for all-cause mortality. Daily functioning was operationalized as basic and instrumental activities of daily living (ADL and IADL) and mobility. Fifty-five percent of the total group declined in ADL, 42 % in IADL, and 38 % in mobility. Thirty-nine percent of the participants with mild ID declined in ADL, 55 % in IADL, and 27 % in mobility. Poor daily functioning and mobility was a risk factor for all-cause mortality. This epidemiological study shows a clear decline in the daily functioning of older adults with intellectual disabilities over a 3-year follow-up period. Care providers should be aware of this decline and focus on maintaining as much independence as possible.
Keywords: Activities of daily living; Deterioration; Mobility; Mortality; People with intellectual disabilities.