Background Functional disability in patients with rheumatoid arthritis (RA) is major concern for clinicians. Although the treatment of RA by anti-rheumatic drugs improve the activities of daily living (ADL), it is difficult to maintain the condition. In RA patients, the progressive deformity and the joint destruction markedly affects their ADL. There are a few studies to examine the risk factors associated with the functional disability of RA using modified health assessment questionnaire (mHAQ) score.
Objectives To investigate the prevalence and the predictors for functional disability of RA patients using mHAQ score.
Methods Two hundred postmenopausal female RA patients (age 61±7.8 years, disease duration 15±10 years, duration after menopause 12±7.3 years, mean ± SD), who were treated in a single hospital were included in the study. The mean follow up period was 2.9 years. Disease activity score (DAS) 28, CRP and ESR were measured, and radiographs of the lateral thoracic and lumbar spine of all the patients were taken to investigate the existence of vertebral fracture (VF) and deformity. All variables were examined twice at both initial and final visits to the hospital.
The patients were divided into two groups by the final mHAQ score; high mHAQ score group (1.0, n=57) and low mHAQ score group (<1.0, n=143). Patient characteristics and radiographic parameters were compared statistically between the groups. Possible risk factors for functional disability were then analyzed by logistic regression analysis. Multivariate models were used to adjust for age, body mass index (BMI), and disease duration.
Results In the investigation and comparison of the demographic and background characteristics between the high mHAQ score group and low mHAQ score group, there was a statistically significant difference in disease duration, mHAQ score, daily dosage of prednisolone (PSL), cumulative dosage of PSL, DAS 28, the prevalence of VF and joint replacement surgery (mean disease duration: 20±10 years vs 13±9.4 years, p<0.001; mean mHAQ score: 1.1±0.5 vs 0.34±0.37, p<0.001; mean daily dosage of PSL: 3.9±2.5 mg/day vs 2.8±2.4 mg/day, p<0.001; mean cumulative dosage of PSL: 6.3±9.1 mg/day vs 3.4±6.0 mg/day, p<0.05; prevalence of VF: 30% vs 13%, p<0.01; prevalence of joint replacement surgery: 30% vs 10%, p<0.001). Final mHAQ score in group with low disease activity (DAS 28 3.2) at baseline was significantly lower than those score in groups with moderate (3.2 < DAS 28 5.1) or high (DAS 28 5.1) disease activity (0.37±0.51, 0.61±0.55, 0.91±0.67, respectively; p<0.01). Final mHAQ score in group with daily PSL 5 mg /day was significantly higher than those with daily PSL below 5 mg/day (0.80±0.59 vs 0.45±0.52, p<0.001).
The multivariate logistic regression model used in the examination of the correlation of high mHAQ score after adjusting for age, BMI and disease duration revealed that the daily dosage of PSL, DAS 28 and existence of VF were associated with functional disability (odds ratio, 1.2, 1.7 and 2.5; 95% confidence interval, 1.0–1.3, 1.2-2.3 and 1.2-5.5, respectively).
Conclusions In postmenopausal RA patients of this study, PSL dosage, disease activity and existence of VF affected the future functional status.
Disclosure of Interest None declared