Minimal important change (MIC) for the Clinical Functioning Information Tool (ClinFIT) in inpatient rehabilitation

OBJECTIVE: To estimate the Minimal Important Change (MIC) for the Clinical Functioning Information Tool (ClinFIT) in inpatient rehabilitation. METHODS: Admission and discharge ClinFIT scores were analyzed in a Royal Melbourne Hospital inpatient rehabilitation cohort. Anchors were the Functional Independence Measure (FIM), EQ-5D-5L index, and EQ visual analog scale (EQ-VAS). Anchor-based analyses included receiver operating characteristic (ROC) analysis, within-patient mean change, and between-group contrasts. Distribution-based reference values were calculated as 0.2 and 0.5 times the baseline ClinFIT SD and 0.2 times the change-score SD. RESULTS: Among 257 patients, mean age was 63.0 years and 54.5% were male. ClinFIT scores improved from 167.0 (SD 59.2) at admission to 97.7 (SD 57.8) at discharge. ClinFIT change correlated most strongly with EQ-5D-5L index change (ρ = -0.68), compared with FIM (ρ = -0.31) and EQ-VAS (ρ = -0.32). ROC-derived thresholds ranged from -77 to -43 points, between-group differences from -76 to -20 points, and distribution-based reference values from -29.7 to -10.3 points. An exploratory range of approximately 50-70 points was proposed based primarily on the ROC-derived thresholds. CONCLUSIONS: The EQ-5D-5L-supported ClinFIT MIC threshold indicated a reduction of approximately 57 points, with a wide confidence interval. ROC-derived thresholds informed an exploratory 50-70-point range.