Development and validation of a shortened and practical frailty index for people with intellectual disabilities

Abstract

Background There is no widely used instrument to detect frailty in people with intellectual disabilities (IDs). We aimed to develop and validate a shorter and more practical version of a published frailty index for people with IDs. Method This study was part of the longitudinal 'Healthy Ageing and Intellectual Disability' study. We included 982 people with IDs aged 50 years and over. The previously developed and validated ID-Frailty Index consisting of 51 deficits was used as the basis for the shortened version, the ID-FI Short Form. Content of the ID-FI Short Form was based on statistics and clinical and practical feasibility. We evaluated the precision and validity of the ID-FI Short Form using the internal consistency, the correlation between the ID-FI Short Form and the original ID-Frailty Index, the agreement in dividing participants in the categories non-frail, pre-frail and frail, and the association with survival. Results Seventeen deficits from the original ID-Frailty Index were selected for inclusion in the ID-FI Short Form. All deficits of the ID-FI Short Form are clinically and practically feasible to assess for caregivers and therapists supporting people with ID. We showed acceptable internal consistency with Cronbach's alpha of 0.75. The Pearson correlation between the ID-Frailty Index and the ID-FI Short Form was excellent (r = 0.94, P < 0.001). We observed a good agreement between the full and short forms in dividing the participants in the frailty categories, with a kappa statistic of 0.63. The ID-FI Short Form was associated with survival; with every 1/100 increase on the ID-FI Short Form, the mortality probability increased by 7% (hazard ratio 1.07, P < 0.001). ConclusionThe first validation of the ID-FI Short Form shows it to be a promising, practical tool to assess the frailty status of people with ID.

Definition, assessment and management of frailty for people with intellectual disabilities: A scoping review

“…Thirteen studies provided information on sex of participants with intellectual disabilities. Twelve of the included studies had similar proportions, with between 46% and 52% being female (Ahlström et al, 2022; El Mrayyan et al, 2022; Hippisley‐Cox & Coupland, 2017; Lin, 2021; Lin & Tseng, 2022; Ouellette‐Kuntz, Martin, & McKenzie, 2018; Ouellette‐Kuntz, Stankiewicz, et al, 2018; McKenzie, Ouellette‐Kuntz, & Martin, 2016b; Martin et al, 2018; Schoufour et al, 2016, 2017, 2022). O'Connell et al (2020) had a slightly higher proportion of females at 58%.…”

“…This is considerably higher than studies with populations of the same age criteria of 50+ using the ID-Frailty Index (Festen et al, 2021;Schoufour et al, 2017), providing further evidence that the CFS is unsuitable for use with this population. While the ID-Frailty Index was recommended (Festen et al, 2021), the ID-FI Short Form may be a preferred option for use in clinical practice due to having fewer items, as well as having good internal consistency (Schoufour et al, 2022 (Lott & Head, 2019) therefore this link may explain this increased risk of frailty. Several studies found frailty to be more common in females in this population, which is consistent with frailty in those without intellectual disabilities (Gordon et al, 2017).…”

“…This is considerably higher than studies with populations of the same age criteria of 50+ using the ID‐Frailty Index (Festen et al, 2021; Schoufour et al, 2017), providing further evidence that the CFS is unsuitable for use with this population. While the ID‐Frailty Index was recommended (Festen et al, 2021), the ID‐FI Short Form may be a preferred option for use in clinical practice due to having fewer items, as well as having good internal consistency (Schoufour et al, 2022). Ouellette‐Kuntz, Martin, and McKenzie (2018) concluded that the HC‐IDD Frailty Index was preferable to the John Hopkins Frailty Marker, again due to it being more appropriate for the population in question, consistent with a paper in the McKenzie, Martin, and Ouellette‐Kuntz (2016a) review (Schoufour, Echteld, & Evenhuis, 2015).…”

“…Festen et al (2021) compared the ID-Frailty Index and the CFS; Schoufour et al, (2022) compared the ID-Frailty Index and the ID-FI Short Form; Ouellette-Kuntz, Martin, and McKenzie (2018) examined the effectiveness of adding the HC-IDD Frailty Index to an existing list of predictors including the John Hopkins Frailty Marker; and Schoufour et al (2017) compared the ID-Frailty Index and Fried's Frailty Phenotype.The ID-Frailty Index was developed bySchoufour et al (2013) and all the studies that investigated this index were from the same research team in the Netherlands. The ID-FI Short Form was developed and validated bySchoufour et al (2022). The HC-IDD Frailty Index was created byMcKenzie et al (2015) and all the studies investigating this tool are by members of this research team based in Canada.…”

Prevalence of frailty syndrome and its predictors in the population of people with intellectual disability compared to the general population: a systematic review

“…In the analyzed studies, this was the way which has been most popular among researchers who used psychological and social tests and interview questionnaires, without taking into account objective laboratory tests (Brehmer, Weber, 2010;Brehmer-Rinderer et al, 2013;Lee et al, 2019;Lin, Tseng 2022;Martin et al, 2018;McKenzie et al, 2015;Ouellette-Kuntz et al, 2018;Schoufour et al, 2013Schoufour et al, , 2015aSchoufour et al, . 2015bSchoufour et al, , 2015cSchoufour et al, , 2016Schoufour et al, , 2022. On the other hand, in general population studies, a complementary way of identifying FS using one-dimensional (phenotypic) and multivariate models has been more often employed to identify FS, which provides a predictive picture of the subject (Fried et al 2001).…”