Background/Purpose: Rheumatoid arthritis (RA) is a chronic, inflammatory disease leading to joint destructions, if untreated. Treatment with biologic DMARDs has shown to favourably influence disease activity, joint destruction, and patient related outcomes (PROs). However, to our knowledge, no studies in larger patient cohorts have investigated the correlation between disease duration with radiographic outcome, disease activity, and disability in the new era of biologic treatment. To analyse cross-sectionally patients with RA for radiographic damage, PROs, and disease activity dependent on disease duration.

Methods: All RA patients from the Swiss national cohort (SCQM) with information on disease duration as documented in the database (time point of diagnosis) were included in the analysis. The primary endpoint was the association between disease duration and the status of radiographic joint destruction, assessed by Ratingen scores (range from 0 to 190, analysed by two independent and blinded assessors) at the last clinical visit in the database. This endpoint was analysed by a multiple negative binomial regression model corrected for confounding factors (gender, age, rheumatoid factor (RF), antibodies to citrullinated protein antigens (ACPA), pre-exposition of anti-TNF drugs or methotrexate). Disease activity (DAS-28) and disability (HAQ DI) were analysed as secondary outcomes.

Results: The original 52’753 records on 8’678 patients resulted in 6’525 evaluable observations with documented Ratingen scores and disease durations. Disease duration ranged between less than 1 and more than 65 years (median 8.3). Anti-TNF drugs were used in 58.4% of patients. We found a significant association between disease duration and the status of radiographic joint destruction with an average increase of Ratingen scores by 8.3% per year of disease duration. RF was the highest predictor for radiographic destruction (estimate 1.41), whereas ACPA positivity was a negative predictor (estimate 0.812). In patients with a disease duration of less than 5 years, clinical disease activity and disability decreased depending on the time since diagnosis. While DAS-28-scores remained on a stable level thereafter (median DAS-28: 2.8, i.e. low disease activity), HAQ-DI scores increased continuously by 0.018 per year of disease duration. DAS-28 and HAQ-DI at the end of follow up correlated moderately (Kendall´s Rank-correlations 0.307) whereas no correlation was found between Ratingen scores and HAQ-DI (-0.009).

Conclusion: In this RA cohort, patients showed cross-sectionally a continuous increase of joint destruction and disability depending on disease duration, despite treatment with biologics and satisfactory control of disease activity, in the majority of patients. Even though, in the era of biologic treatment, a satisfactory control of disease activity can be achieved in most patients, RA remains a progressive disease leading to joint destruction.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/radiographic-damage-in-patients-with-ra-increases-by-8-3-per-year-disease-duration-in-the-era-of-biologic-dmards-results-from-the-scqm-cohort/