Minimal clinically important differences in the Carpal Tunnel Questionnaire after carpal tunnel release

Abstract

Minimal clinically important difference is the smallest difference in the score of an outcome instrument that patients perceive as important. A prospective observational study was conducted involving 66 consecutive patients undergoing limited open carpal tunnel release. Patients completed the Carpal Tunnel Questionnaire (CTQ) before surgery and 3 months post-surgery. A transition item for patient satisfaction after 3 months of surgery was used as an anchor. Receiver operator characteristic curves were used to determine the minimal clinically important differences for the CTQ and its two subscales that best separated satisfied and unsatisfied patients. A 0.92 point change in the CTQ, a 1.14 point change in the symptom subscale, and a 0.74 point change in the function subscale indicated a clinically relevant threshold of satisfaction, and those values were greater than what could be accounted for by measurement errors. © The Author(s) 2012.