Development of a frailty index for older people with intellectual disabilities: results from the HA-ID study

Although there is no strict definition of frailty, it is generally accepted as a state of high vulnerability for adverse health outcomes at older age. Associations between frailty and mortality, dependence, and hospitalization have been shown. We measured the frailty level of older people with intellectual disabilities (ID). Furthermore variation in gender, age, and level of ID were identified. Results were compared to a frailty study in the general European population.

This research elaborates on a large cross-sectional study: Healthy Ageing with Intellectual Disability (HA-ID). Nine hundred-eighty-two men and women (≥ 50 yr) with ID were included. Based on the collected data, we developed a frailty index with 51 health-related deficits, and calculated a frailty index score between 0 and 1 for each individual. Deficits included physical, social and psychological problems.

The mean frailty index score was 0.27 (standard deviation .13). Frailty was positively correlated with age (r=0.297, p<.001). More severe ID was associated with higher frailty scores (β=0.440, p<001). The upper limit of the FI was 0.69, which was consistent for all age categories.

As people with ID are getting older, the question whether additional years are spent in good health becomes salient. Here, people with ID over age 50 had frailty scores similar to most elderly people over 75 y. Future research is needed to confirm if frail elderly people with ID have an increased risk of adverse health outcomes.