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

•The Minimal Clinically Important Difference (MCID) allows for measuring the improvement of patients.•The MCID can be used to better manage treatment.•Knowing the MCID of the Hand Function Sort questionnaire (HFS) can improve communication between therapists.•In vocational rehabilitation, the HFS is used to predict the ability to resume work. 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. 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). We included 225 patients. By the anchor-based method, the MCID for the HFS-F and DASH was +26 (SD 35) (P