Influence of gender on assessments of disease activity and function in early rheumatoid arthritis in relation to radiographic joint damage

Objective: To evaluate gender differences in score on 28-joint Disease Activity Score (DAS28), Health Assessment Questionnaire (HAQ) and Signals Of Functional Impairment (SOFI) and to relate these scores to radiographic joint destruction. Methods: In all, 549 patients with early RA (62% women) from the BARFOT (for "Better Anti-Rheumatic FarmacOTherapy'') study were included. At baseline, 1, 2 and 5 years DAS28, HAQ and SOFI scoring, and radiographs of hands and feet were performed. The radiographs were scored using the van der Heijde-Sharp score. Results: In women the DAS28 was significantly higher than in men due to higher scores for general health and tender joints. Likewise, HAQ and VAS pain were rated significantly higher in women. The SOFI score was worse in men during the first 2 years, depending on higher upper limb scores. Total Sharp score (TotSharp), erosion score and joint space narrowing score did not differ between the sexes at any time point. The DAS28 area under the curve (AUC) correlated significantly with TotSharp at 5 years in both genders (r = 0.316, r = 0.313) mainly owing to swollen joints and erythrocyte sedimentation rate (ESR). The SOFI AUC correlated significantly with TotSharp in women (r = 0.135 to 0.220) but not in men. Conclusions: Despite a similar degree of radiographic joint destruction women had, compared with men, worse scores for DAS28 and HAQ, possibly due to higher pain perception and less muscular strength and perhaps because men overestimate their functional capacity.