The minimal clinically important difference of the Michigan hand outcomes questionnaire

Abstract

Purpose: To determine the change in score required in various domains of the Michigan Hand Outcomes Questionnaire (MHQ) to indicate meaningful patient improvement, or the minimal clinically important difference (MCID), for 3 common hand conditions: rheumatoid arthritis (RA), carpal tunnel syndrome (CTS) and distal radius fracture (DRF).

Methods: The MHQ was administered to patients at 2 time points. Patient satisfaction was defined as a satisfaction score > or =80% of the standard deviation of that patient sample. The minimal change in score in specific MHQ domains that corresponded with patient satisfaction was determined using receiver operating characteristic curves.

Results: For CTS patients, MCIDs of 23, 13, and 8 were identified for the pain, function, and work domains, respectively. For RA patients, pain and function were also identified as having discriminative ability, with MCIDs of 11 and 13, respectively. An MCID of 3 was identified for the activities of daily living domain. For DRF patients, no MHQ domains showed discriminative ability because of the ceiling effect at the 3-month assessment period.

Conclusions: Individual domains of the MHQ can be used to discriminate between patients who are satisfied and those who are not after either carpal tunnel release or silicone arthroplasty of the metacarpophalangeal joints for RA. Pain and function are the domains of the MHQ that are best able to discriminate between patients who are satisfied and those who are not. The identical function MCID for both RA patients and CTS patients, despite markedly different preoperative values, indicates that a standard amount of functional change may indicate patient satisfaction. High postoperative satisfaction, even only 3 months after surgery, prevented any domains from showing discriminative ability for the DRF patients.

Figure 1

ROC curve - Swanson metacarpophalangeal arthroplasty for rheumatoid arthritis Arrows indicate the MCIDs, the points closest to the upper left quadrant of the graph, where sensitivity is closest to 1 and 1-specificity is closest to 0.

Figure 2

ROC curve – Limited-incision technique carpal tunnel release Arrows indicate the MCIDs, the points closest to the upper left quadrant of the graph, where sensitivity is closest to 1 and 1-specificity is closest to 0.