Comparison of the responsiveness of the FIM and the interRAI post acute care assessment instrument in rehabilitation of older adults.

Abstract

To compare the responsiveness of 2 major systems developed for rehabilitation settings--the FIM and the interRAI Post Acute Care (PAC) assessment--in older patients. Trained raters assessed patients with both tools at admission and discharge. Musculoskeletal (MSK) and geriatric rehabilitation units (GRUs) in 2 rehabilitation hospitals. Older adults receiving rehabilitation (N=208; mean age +/- SD, 78.5+/-9.3; 67% women). Not applicable. Responsiveness was evaluated using effect size (ES) and standardized response mean (SRM). ES and SRM were somewhat higher for the FIM motor (GRU ES=1.68, SRM=1.31; MSK ES=2.12, SRM=2.25) than the PAC (GRU ES=1.64, SRM=1.29; MSK ES=1.57, SRM=1.89) in both patient groups. Both tools were more responsive in MSKs than GRUs. This may reflect the greater frailty and clinical complexity of GRU patients. Both the FIM motor and the PAC were able to detect clinically relevant improvement in functional ability in older rehabilitation inpatients.