Radiographic outcome over 15 years in patients with early rheumatoid arthritis – a BARFOT-study

OBJECTIVES: To investigate the progression of radiographic damage in hands and feet of patients with early rheumatoid arthritis monitored prospectively for 15 years, and to search for predictors. METHODS: This study comprises 990 patients from the BARFOT cohort, included 1992-2006. Radiographs of the hands and feet were performed over time and evaluated by the Sharp van der Heijde scoring (SHS) method. The patients were divided into three clusters, using progression over 15 years of erosion score and joint space narrowing score. The cluster analyses were conducted using K-means cluster analysis. Disease activity was measured by Disease Activity Score 28 (DAS28) and erythrocyte sedimentation rate (ESR), and physical function by Health Assessment Questionnaire (HAQ). RESULTS: Cluster 1 consisted of 54, cluster 2 of 258 and cluster 3 of 678 patients. Of the patients with the highest radiographic progress during the 15 years (cluster 1), 59% were included in the 1990s, and they were overall more often seropositive (94%), and had at baseline higher SHS, and lower DAS28. Of the patients with the smallest radiographic progression (cluster 3), 45% were included in the 1990s, and they were overall less often seropositive, had at baseline lower SHS, higher DAS28 and higher tender joint count (TJC). At baseline, there was no difference in the choice of treatment between the clusters. From the two-year follow-up, a higher proportion of patients in cluster 3 were untreated. Seropositivity and less tender joints predicted belonging to cluster 1, whereas besides seropositivity also older age, female sex, and erosions at baseline predicted belonging to cluster 2. The worse radiographic progression in cluster 1 and 2 was associated with higher DAS28 throughout the 15 years, and with worse HAQ at both 8 and 15 years, compared with cluster 3. CONCLUSIONS: This study highlights the presence of distinct subgroups of rheumatoid arthritis, which points to the importance of early and individualised treatment strategies.