Functional disability in relation to radiological damage and disease activity in patients with rheumatoid arthritis in remission

Objective. To investigate the relationship between functional disability, disease activity and radiological damage in patients with rheumatoid arthritis (RA) in remission. Methods. One hundred and eighty-six patients with RA in remission or with low disease activity were studied. The following variables were assessed at one time point: joint count, visual analog scale for pain, functional disability, i.e., health assessment questionnaire (HAQ) score, radiological joint damage as assessed by radiographs of hands and feet and scored according the Sharp-van der Heijde method, and presence of comorbidity. Disease activity was expressed as the disease activity score (DAS). Correlations were calculated by Spearman's rho coefficient of correlation. In addition, variables associated with the score were analyzed by logistic regression. Results. The median HAQ score was 0.25 [interquartile (IQR) range 0-0.75] and the median DAS was 1.0 (IQR 0.7-1.5). Of the 186 RA patients included, 82% were in remission according to the DAS. The median joint damage as assessed by the Sharp-van der Heijde score was 21 (IQR 9-74). Functional disability was significantly correlated with pain (rho 0.48. p < 0.001), disease activity (rho 0.42; p < 0.001), disease duration (rho 0.39; p < 0.001), radiographic joint damage (rho 0.37; p < 0.001), and age (rho 0.19; p = 0.01). In a logistic regression model functional disability was independently related to presence of pain, disease activity, radiographic joint damage and disease duration in decreasing order of strength, but not to age, sex and co-morbidity. Conclusion. Patients with RA who are in remission might experience minimal functional disability and radiographic joint damage. Functional disability in RA patients in remission is most strongly related to the presence of pain and in lesser extent to disease activity, radiographic joint damage, and disease duration.