Determining the minimal clinically important difference of the hand function sort questionnaire in vocational rehabilitation.

OBJECTIVE: To estimate the Minimal Clinically Important Difference (MCID) of the French version of the Hand Function Sort questionnaire (HFS-F). As a comparison, the MCID of the Disabilities of the Arm, Shoulder, and Hand (DASH) was also estimated.

MATERIALS AND METHODS: We included French-speaking patients hospitalized in a multidisciplinary rehabilitation program for chronic pain of the upper limb after an accident. HFS-F and DASH scores were collected at admission and discharge; the Patient Global Impression of Change measure (PGIC; 7 levels) was collected at discharge. The MCID was estimated by 2 methods: the anchor-based method (receiver operating characteristic [ROC], delta (Δ) mean of scores) and the objective method based on the distribution of scores (standard error of measurement, SEM).

RESULT: We included 225 patients. By the anchor-based method, the MCID for the HFS-F and DASH was +26 (SD 35) (P<10-4 ) and -13 (SD 13) (P<10-4 ), respectively, and by the ROC curve, it was +10 to +12 for the Δ-HFS-F and -7.5 to -5 for the Δ-DASH. The area under the ROC curve (AUC) was 0.726 [0.638-0.781] for Δ-HFS-F and 0.768 [0.701-0.83] for Δ-DASH. The correlations between the anchor and delta scores were>0.38 (P<10-4 ). The SEM was 16.2 for the HFS-F and -4.3 for the DASH.

CONCLUSIONS: Values below the SEM must be rejected. Our anchor was significantly correlated with the outcome. Therefore, we propose an MCID for the HFS-F of 26, corresponding to approximately 10% progression of the score.