Background Rheumatoid arthritis (RA) is an inflammatory disease with a chronic course over many years. Long-term observations in the late 90s have demonstrated that RA is associated with progressive articular destruction and increasing disability over the course of the disease. When biologic treatment was introduced, a lot of studies were able to show a favourable influence on disease activity, joint destruction, and disability. However, to our knowledge, no long-term studies have been conducted investigating the radiographic outcome and disability in this new era of treatment with biologics.
Objectives To analyse patients with RA for radiographic damage, disability and disease activity dependent on disease duration.
Methods We included all RA patients from the Swiss Clinical Quality Management in rheumatoid arthritis (SCQM) with at least one clinical visit and information on the disease duration available in the database. The primary endpoint was the association between the radiographic destruction, assessed by Ratingen erosion scores at the last clinical visit, and disease duration. This endpoint was investigated by a multiple negative binomial regression model which corrected for the effect of gender, age, rheumatoid factor (RF), ACPA and therapeutic status regarding the use of anti-TNF drugs and methotrexate (MTX), as possible confounding factors. Disease activity (DAS 28) and disability (HAQ DI) in dependence of disease duration served as secondary outcomes, analysed by using a multiple linear regression model with corrections for the same potential confounders as described for the primary endpoint.
Results The original 52'753 records on 8'678 patients resulted in 6'526 evaluable observations for the Ratingen score. Disease duration ranged between less than 1 and more than 65 years, with a median disease duration of 8.3 years, and past or current use of anti-TNF drugs in 58.4% of patients. We found a significant association between disease duration and radiographic destruction with an average increase of Ratingen scores by 8.3% each year (95%CI from 8.1% to 8.6%). The most significant predictor for less radiographic destruction was a negative rheumatoid factor. During the first 5 years of the disease, clinical activity and disability decreased over time. While DAS 28-scores remained on a stable level in patients with a disease duration of more than 5 years (median DAS 28 of 2.8), HAQ-DI scores increased continuously by 0.018 for each additional year.
Conclusions In this RA cohort, patients showed a continuous increase of articular destruction and physical disability in parallel to disease duration, despite treatment with biologics in the majority of patients. Even though in the era of biologics a satisfactory control of disease activity can be achieved in most patients, RA remains a progressive disease leading to joint destruction and physical disability.
Disclosure of Interest None declared