Determining the Minimally Important Change of the Michigan Hand outcomes Questionnaire in patients undergoing trigger finger release

Introduction: The Michigan Hand outcomes Questionnaire (MHQ) is a widely used instrument to evaluate treatment results for hand conditions. Establishing the Minimally Important Change (MIC) is essential for interpreting change in outcome that is clinically relevant.

Purpose of the study: The purpose of this study was to determine the MIC of the MHQ total and subscale scores in patients undergoing trigger finger release.

Study design: This is a prospective cohort study conducted between December 2011 and February 2020.

Methods: Patients completed the MHQ prior to surgery and 3 months postoperatively. The MIC of the MHQ was determined using 5 anchor-based methods (ie, 2 anchor mean change methods and 3 receiver operating characteristic methods). The median MIC value was determined to represent the triangulated MIC.

Results: A total of 1814 patients were included. The MIC for the MHQ total score ranged from 7.7 to 10.9, with a triangulated estimate of 9.3. The MIC estimates for 5 of 6 of the MHQ subscales ranged from 7.7 to 20.0. No MICs could be determined for the MHQ subscale "aesthetics" due to low correlations between the anchor questions and MHQ change scores.

Conclusions: These MIC estimates can contribute to the interpretation of clinical outcomes following trigger finger release and for assessment of power in prospective trials.