In 2004, we initiated an inception cohort of patients with recent-onset rheumatoid arthritis (RA). Hand function was incorporated into evaluations from 2014 onward. The objectives were to examine hand function in our cohort, compare hand function with function in healthy controls and determine the factors associated with impaired function.
From February 2014 to June 2015, 139 patients (97.2 % of the cohort) had disease activity scored (28 joints, [DAS28]); the Michigan Hand Outcome Questionnaire (MHQ) and Disabilities of the Arm, Shoulder and Hand Outcome Measure (DASH) were completed, and the tip-, key- and palmar-pinch and grip strengths were measured. Sixty-nine healthy controls underwent the same evaluations. Ninety-nine patients underwent a second evaluation one year after their baseline. Descriptive statistics and linear regression models were used. Patients and controls signed informed consent.
Patients were primarily middle-aged females with a median disease duration of 7 years; 91 patients had DAS28-remission, and 16, 23, and 9 patients had low, moderate and high disease activity, respectively. Controls scored better than did patients with (any) disease activity level; remission patients had similar DASH and key pinch function as did controls with poorer MHQ and both tip and palmar pinch and grip strength. DAS28 was consistently associated with impaired hand function. Among the patients with a one-year re-assessment, changes in DAS28 correlated (rho = 0.34 to 0.63) with changes in hand function (p ≤ 0.01 for all comparisons), but there was no correlation with palmar pinch strength.
Disease activity was associated with hand function impairment in RA patients with variable follow-up. MHQ discriminated poorer hand function in remission patients who otherwise had similar DASH scores as the controls did.