Is it possible to predict radiological damage in early rheumatoid arthritis (RA)? A report on the occurrence, progression, and prognostic factors of radiological erosions over the first 3 years in 866 patients from the Early RA Study (ERAS).

Our aim was to assess the occurrence, progression, and prognostic features for radiological damage in early rheumatoid arthritis (RA). We recruited an inception cohort of patients from rheumatology departments in 9 hospitals beginning in 1986. Standard clinical and laboratory assessments and radiographs of hands and feet were made at baseline and yearly, and scored using Larsen's method. The study included 866 patients with radiographic scores at baseline and at 3 years, of whom 279 (32%) had erosive damage at baseline, and 609 (70%) by 3 years. Baseline and first-year values for Larsen erosion score, rheumatoid factor (RF), erythrocyte sedimentation rate (ESR), hemoglobin, nodules, swollen joint count, grip strength, duration of symptoms, and presence of RA-associated shared epitope were all risk factors for 3 year radiological outcome. In the non-erosive group at baseline (68%), high RF and ESR correctly predicted erosions or not by 3 years in 67%. Severity of erosions was correctly predicted by Larsen and swollen joint scores at baseline (82% correct), and Larsen score and ESR at one year (90% correct). In conclusion, most patients had evidence of radiological erosions by 3 years, despite early treatment with conventional drug therapy. Prognosis for radiological outcome was possible using routinely obtained clinical and laboratory measures. Ninety percent correct classification, even at one year, is likely to be useful to clinicians managing treatment options in early RA.