The relationship between disease activity, joint destruction, and functional capacity over the course of rheumatoid arthritis

Abstract

Objective To investigate the relationship between functional capacity, disease activity, and joint destruction over the course of rheumatoid arthritis (RA). Methods The followup data on 378 patients with early RA (duration <1 year), included in an open, prospective study since 1985 at the Department of Rheumatology of the University Medical Center Nijmegen, were used. Functional capacity, disease activity, and joint destruction were assessed using the Health Assessment Questionnaire disability index (HAQ DI), the Disease Activity Score (DAS), and a modification of the sharp radiographic damage score, respectively. Multiple linear regression was used to model the data collected at 0, 3, 6, and 9 years after study start, to investigate which variables influenced functional capacity during the disease course. A general linear mixed model for longitudinal data, which included the variables identified as significant in the multiple linear regression models and several interaction terms between the variables, was run. Results On average, the functional capacity of the patients, as measured by the HAQ DI, worsened over the course of the disease after an initial improvement. After an initial reduction in the extent of disease activity, the mean DAS remained more or less stable over the course of the disease. The mean modified sharp joint damage score worsened over the course of the disease, with a slower progression rate later in the disease. In the multiple linear regression at 0, 3, and 6 years after study start, disease activity was found to be an important factor influencing functional capacity, and at 6 and 9 years, joint damage had an important effect on functional capacity. Furthermore, at 6 and 9 years, there was an interaction effect of joint destruction with disease activity. In the general linear mixed model, disease activity, joint damage, and an interaction effect of disease activity and joint damage were the main factors explaining functional capacity. Conclusion The effect of disease activity and joint destruction on functional capacity changes over the course of the disease. In early RA, functional capacity is most associated with disease activity, and in late disease, with joint damage.

Predictors of joint damage in patients with early rheumatoid arthritis treated with high‐dose methotrexate with or without concomitant infliximab: Results from the ASPIRE trial

“…Progressive joint destruction is a hallmark of RA, and over time, is associated with poor functional outcome (4,6,38). Although DMARD therapy can interfere with the disease process, it is difficult to predict which patients with RA will respond adequately to various treatments.…”

“…While progression of radiographic abnormalities may have limited implications with regard to function in the short term, accumulation of destruction over time translates into a decline of functional capacity and quality of life (4)(5)(6). Both functional decline and radiographic progression have been strongly associated with continued disease activity as reflected by persistent elevations in swollen joint counts, the acute-phase response, or disease activity scores derived from composite indices (4,(6)(7)(8)(9)(10)(11)(12)(13). These relationships have been established from previous studies of the natural course of RA and from results of clinical trials of treatments that are no longer the standard of care (14)(15)(16).…”

Remission and active disease in rheumatoid arthritis: Defining criteria for disease activity states

“…Rheumatoid arthritis (RA) often causes severe joint destruction and disability (1)(2)(3)(4)(5)(6), and treatment with disease-modifying antirheumatic drugs significantly improves outcome (7)(8)(9)(10)(11). For these reasons, a clear assessment of a patient's overall disease activity and responses to treatment modifications is important.…”

Synovial membrane cytokine expression is predictive of joint damage progression in rheumatoid arthritis: A two‐year prospective study (the DAMAGE study cohort)

“…Rheumatoid arthritis (RA) is characterized by progressive irreversible joint damage resulting in increasing disability (1,2). However, joint damage accumulation is highly variable, differing up to 10-fold between individuals after 8-12 years of disease (3,4).…”