Objective
Millions of patients suffer from the disabling hand manifestations of rheumatoid arthritis (RA), yet few hand-specific instruments are validated in this population. Our objective is to assess the reliability, validity, and responsiveness of the Michigan Hand Questionnaire (MHQ) in RA patients.
Methods
At enrollment and at 6 months, 128 RA patients with severe subluxation of the metacarpophalangeal joints completed the MHQ, a 37-item questionnaire with 6 domains: function, activities of daily living (ADL), pain, work, aesthetics, and satisfaction. Reliability was measured using Spearman correlation coefficients (r) between time periods. Internal consistency was measured using Cronbach’s α. Construct validity was measured by correlating MHQ responses with the Arthritis Impact Measurement Scale 2 (AIMS2). Responsiveness was measured by calculating standardized response means between time periods.
Results
The MHQ demonstrated good test-retest reliability (r = 0.66, p<0.001). Cronbach’s α scores were high for ADL (α=0.90), function (α=0.87), aesthetics (α=0.79), and satisfaction (α=0.89), indicating redundancy. The MHQ correlated well with AIMS2 responses. Function (r=−0.63), ADL (r=−0.77), work (r=−0.64), pain (r=0.59), and summary score (r=−0.74) were correlated with the physical domain. Affect was correlated with ADL (r=−0.47), work (r=−0.47), pain (r=0.48), and summary score (r=−0.53). Responsiveness was excellent among arthroplasty patients: function (SRM=1.42), ADL (SRM=0.89), aesthetics (SRM=1.23), satisfaction (SRM=1.76), and summary score (SRM=1.61).
Conclusions
The MHQ is easily administered, reliable and valid to measure rheumatoid hand function, and can be used to measure outcomes in rheumatoid hand disease.
