Although a relationship between joint destruction and functional disorders seems apparent in patients with rheumatoid arthritis (RA), it has not been well proven in the literature. The aims of this study were to clarify the relationship between roentgenographic joint destruction in the hands and functional disorders in patients with RA, and to explore the appropriate assessment measures for functional disorders.
Cross-sectional data of the Genant-modified Total Sharp Score (Genant-mTSS), Health Assessment Questionnaire-Disability Index (HAQ-DI), Disabilities of the Arm, Shoulder, and Hand (DASH), and Michigan Hand Outcomes Questionnaire (MHQ) were collected from 50 consecutive RA patients and analyzed.
HAQ-DI, DASH, and MHQ had close correlations with Genant-mTSS, with correlation coefficients of 0.69, 0.71, and -0.70, respectively, among patients with low disease activity (DAS28 < 3.2). A floor effect was observed in HAQ-DI, but neither floor nor ceiling effects were observed in DASH and MHQ. Both DASH and MHQ were strongly correlated with HAQ-DI, with correlation coefficients of 0.87 and 0.73, respectively.
Functional disorders had significant relationships with roentgenographic joint destruction in the hands among RA patients with low disease activity. As assessment measures of functional disorders, DASH and MHQ had no floor or ceiling effects, being different from HAQ-DI.