Background Small joints of the hands and wrists are universally affected in rheumatoid arthritis (RA) and hand function (HF) may be impaired; few indices include HF assessment, beyond swollen and tender joint counts.
Objectives To evaluate HF in RA patients from an early arthritis clinic initiated in 2004, to compare it with HF from paired controls and to identify factors associated to impaired function.
Methods From February 2014 to June 2015, 139 patients currently attending the clinic (97.2% of the cohort) had disease activity scored (DAS28) and tip-, key- and palmar-pinch and grip strength measured as recommended (1); in addition, patients completed the Michigan Hand Outcome Questionnaire (MHQ) (2) and the Disabilities of the Arm, Shoulder and Hand Outcome Measure (DASH) (3). Sixty-nine paired (according to age ±5 years and gender) controls had same evaluations (but DAS28). Cut-offs for normal tests were obtained from normative data and controls values (median + 1 SD). Descriptive statistics and regression analysis were used. Patients and controls signed informed consent.
Results Patients were more frequently middle-aged (44.1± 13.1 years) female (89.2%) with median disease duration of 7 years (IQR: 3–9 years) at HF assessment; of them, 91 patients had DAS28-remission, 16 low disease activity, 23 moderate and 9 patients had high disease activity. Controls (age: 43.8±11.5 years, 89.9% female) scored better HF tests and questionnaires than patients with (any) disease activity; nonetheless, remission patients had similar DASH and key pinch than controls but worse MHQ (92.5 vs. 98.9), grip strength (18.7 vs. 22.3), tip pinch (3.8 vs. 4.5) and palmar pinch (5 vs. 6), (p=0.000 for all comparisons). DAS28 was consistently associated to HF impairment (β coefficient from 2.2 to 2.7, p≤0.05); additional predictors were age and gender. Cut-off for DAS28 to predict normal HF varied (according to HF assessment, i.e, MHQ, DASH, grip strength or pinches) from 1.8 to 2.9. MHQ and DASH were highly correlated; pinches had moderate correlations with questionnaires and grip strength had the best correlation (rho=0.6 for either MHQ or DASH).
Conclusions Disease activity consistently predicted HF in a cohort of RA patients with variable follow-up. Additional predictors were age and gender. Remission's patients showed similar HF performance to controls, when evaluated by DASH and key pinch although the MHQ and grip strength measurement identified impairment of their HF. Routine assessment of RA patients should include a comprehensive evaluation of HF; according to our results, we propose grip strength and MHQ to assess it.
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Waljee JF, Chung KC, Kim HM et al. Validity and responsiveness of the Michigan Hand Questionnaire in patients with Rheumatoid Arthritis: A multicenter International Study. Arthritis Care Res 2010; 62: 1569–77.
Raven EE, Haverkamp D, Sierevelt IN et al. Construct validity and reliability of the disability of arm, shoulder and hand questionnaire for upper extremity complaints in rheumatoid arthritis. J Rheumatol 2008; 35: 2334–8.
Disclosure of Interest None declared