Predicting disabilities in daily functioning in older people with intellectual disabilities using a frailty index

Frailty is a state of increased vulnerability to adverse health outcomes compared to others of the same age. People with intellectual disabilities (ID) are more frequently and earlier frail compared to the general population. Frailty challenges much of health care, which will likely further increase due to the aging of the population. Before effective interventions can start, more information is necessary about the consequences of frailty in this, already disabled, population. Here we report whether frailty predicts disabilities in daily functioning. Frailty was measured with a frailty index (FI). At baseline and follow-up activities of daily living (ADL), instrumental activities of daily living (IADL) and mobility were collected by informant report. For 703 older people with ID (≥50 yr) baseline and follow-up measures were known. Multivariate linear regression models were used to predict ADL, IADL and mobility at follow-up. The FI was significantly associated with disabilities in daily functioning independent of baseline characteristics (age, gender, level of ID, Down syndrome) and baseline ADL, IADL or mobility. The FI showed to be most predictive for those with relative high independence at baseline. These results stress the importance for interventions that limit the progression of frailty and, thereby, help to limit further disability.