Objective: To validate Sections GG (Self-Care and Mobility Assessment), B (Hearing, Speech, and Vision), and C (Cognitive Patterns) of the Centers for Medicare and Medicaid Services Inpatient Rehabilitation Facility Patient Assessment Instrument (CMS-IRF PAI) Version 1.4 in comparison with Functional Independence Measure (FIM) motor subscale (FIMm) and cognitive subscale (FIMc).
Design: Retrospective cohort.
Setting: Single inpatient rehabilitation facility.
Participants: Cohort of 1296 patients admitted for rehabilitation after stroke, between October 1, 2016, and October 1, 2019.
Interventions: Not applicable.
Main outcome measures: Sections GG, B, and C scores were compared with FIMm and FIMc using Spearman's and Bland-Altman Analyses.
Results: Sections GG and FIMm were highly correlated on admission (ρ=0.919, P<.001) and discharge (ρ=0.929, P<.001). Ceiling effects at discharge were more pronounced for Section GG (8.6%). Bland-Altman analyses revealed a bias toward higher scores on Section GG vs FIMm on admission (Bias=2.3%, P<.001), and discharge (Bias=6.2%, P<.001). Section GG showed bias toward greater gains in function (Bias=3.9%, P<.001), particularly in walking and stairs (bias=3.71%, P<.001). Comparable self-care items accounted for a smaller percentage of the Section GG gains compared with FIMm (bias=-7.5%, P<.001). The internal validity of a scale consisting of Section B and C (B+C scale) was good, (Cronbach's alpha=0.868) and was highly correlated with FIMc (ρ=0.745), but rated patients at a higher level of cognition (bias=20.0%, P<.001) and had a greater ceiling effect (20.4%) on admission compared with the FIMc (0.6%).
Conclusion: The B+C scale and Section GG were correlated with FIMc and FIMm subscales but biased toward higher ratings of ability. Ceiling effects may limit discrimination at higher level of cognition/functional independence. The clinical acceptability of Section GG total scores as an outcome measure and predictor of long-term outcomes requires further study.
Keywords: Activities of daily living; Health Services Administration; Outcome and process assessment; Rehabilitation; Validity.
Published by Elsevier Inc.