Frailty and Activities of Daily Living in Adults with Intellectual Disability

Background While adults with Intellectual Disability (ID) are at increased risk of frailty, accurate frailty measurement is challenging in this population. Lifelong functional dependence can be misrepresented as frailty using existing frailty indices (FIs). An ID-specific FI has been developed that omits markers of activities of daily living (ADLs) to limit the bias of pre-existing dependency in frailty measurement. The aim of this study was to examine dependency in ADL ability as an outcome of frailty measured using an ID-specific FI. Methods This cross-sectional study was conducted using the Intellectual Disability Supplement to The Irish Longitudinal Database of Aging (IDS-TILDA). Frailty was measured using the IDS-TILDA FI, a 31-item FI. The IDS-TILDA FI contains no markers of functional dependence. Frailty was measured in 745 adults with ID using data from Wave 1 of IDS-TILDA (2010-2011). Frailty is scored from 0-1 with higher scores indicating higher frailty. The outcomes of interest were personal and instrumental ADLs; Bathing, toileting, shopping and household chores. Pearson correlation was used to examine the relationship between frailty and ADL ability while controlling for age and Level of ID. Statistical analysis was conducted using SPSS Version 29.0.0. Results After controlling for age and level of ID, the IDS-TILDA FI was significantly associated with functional tasks. The strongest correlations were observed for toileting (r = .235, p < .001) and bathing (r = .191, p < .001). Weaker but still significant associations were found for household chores (r = .132, p < .001) and shopping (r = .097, p = .013). Conclusion Frailty appears to have an independent effect on individuals’ ability to perform both personal and instrumental activities of daily living. Stronger associations were observed for personal ADLs over instrumental ADLs, particularly after controlling for Level of ID. These results suggest that frailty can be accurately measured without inclusion of functional ability.