Minimal clinically important difference of the Michigan Hand Outcomes Questionnaire score and the pain visual analogue scale in conservative treatment of trigger finger

We investigated the minimal clinically important difference (MCID) of the Michigan Hand Outcomes Questionnaire (MHQ) and the pain visual analogue scale (VAS-pain) after conservative treatment of trigger finger. This secondary analysis of a randomized controlled trial compared pain reduction, symptoms and functional improvement at 12 weeks. Patients included were at least 18 years old and able to complete MHQ and VAS-pain at enrolment and 12 weeks after treatment. The MCIDs of MHQ and VAS-pain were evaluated using a distribution-based, anchor-based and receiver operating characteristic (ROC) curve-based approach. Of the 117 patients, the MCIDs of MHQ and VAS-pain using a distribution-based approach were 5.3 and 0.6, respectively; applying ROC method were 23.5 and 2.5, respectively; and using anchor questions were 15 and 2, respectively. These MCID values by anchor-based method with a minimal difference of 15 for MHQ and 2 for VAS-pain are recommended as primary evidence to determine clinically significant improvement after conservative treatment of trigger finger. Level of evidence: I