The Correlation between Lower Limb Disability and Laboratory and Clinical Findings ‎in Patients with Rheumatoid Arthritis

(1) To evaluate the correlation between lower limb disability and activity and severity parameters including number of swollen joints, number of sensitive joint, morning stiffness time and Ritchie Articular Index (RAI)). (2) To investigate its known-group validity of RAOS questionnaire by Rheumatoid Factor (RF), Erythrocyte Sedimentation Rate (ESR) and C-reactive Protein (CRP).234 patients with RA were requested to complete the Persian version of Rheumatoid and Arthritis Outcome Score (RAOS measures the patients’ opinion about their leg and associated problems). This cross-sectional study was performed in year 1400 in Iranian rheumatology center. Activity and severity parameters were recorded by rheumatologist. Finally, RF, ESR and CRP were evaluated using blood test. Spearman’s correlations between the RAOS subscales and the number of tender joints and swollen joints, duration of joint stiffness, RAI, pain and Health ranged between 0.51 and 0.74. In addition, Mann-Whitney U tests showed significant difference of PHAQ-DI scores between known groups of positive and negative states of CRP and ESR. In regression analysis, pain and health variables were significantly correlated to almost all subscales of the RAOS questionnaire.The Persian version of RAOS questionnaire is a valid questionnaire for measuring the disability in RA patients.