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

Abstract

Objective: 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.

Design: Trained raters assessed patients with both tools at admission and discharge.

Setting: Musculoskeletal (MSK) and geriatric rehabilitation units (GRUs) in 2 rehabilitation hospitals.

Participants: Older adults receiving rehabilitation (N=208; mean age +/- SD, 78.5+/-9.3; 67% women).

Interventions: Not applicable.

Main outcome measures: Responsiveness was evaluated using effect size (ES) and standardized response mean (SRM).

Results: 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.

Conclusions: Both the FIM motor and the PAC were able to detect clinically relevant improvement in functional ability in older rehabilitation inpatients.