Changes at Presentation in Patients With Early Rheumatoid Arthritis: A 24-Year Study of the Early Undifferentiated Polyarthritis (EUPA) Cohort.

Objective: To analyze changes in baseline characteristics of patients with very early rheumatoid arthritis (RA) over 24 years in the Early Undifferentiated Polyarthritis (EUPA) cohort.

Methods: Consecutive patients with recent-onset polyarthritis fulfilling RA classification criteria recruited in EUPA were assessed at baseline. Three successive periods were defined: (1) prior to the general availability of biologics (1998-2004; 245 patients), (2) prior to the implantation of the 2010 classification criteria (2005-2010; 266 patients), and (3) the most recent decade (2011-2022; 329 patients).

Results: At baseline, demographics, BMI, swollen and tender joint counts, proportion fulfilling 2010 American College of Rheumatology/European Alliance of Associations for Rheumatology criteria, modified Health Assessment Questionnaire, shared epitope status, patient-reported outcomes except pain, and patient global assessment of disease activity remained stable over the 3 periods. Despite a marked decrease in active smoking (22.2% to 12.1%), prevalence of cardiovascular comorbidities and prior cancer increased. Although duration of symptoms increased from a median of 2.9 to 4.1 months, decreases were seen in seropositivity (53.9% to 42.2%) and C-reactive protein beginning in the 2005-2010 period. A large decrease in erosive status (Sharp/van der Heijde erosion score ≥ 5; 18.3% to 9.4%) was only observed after 2011; this decrease occurred mostly in seronegative patients. Use of disease-modifying antirheumatic drugs prior to inclusion remained low and stable (25.7%), but use of oral corticosteroids increased (18% to 33.4%).

Conclusion: Baseline characteristics of patients with RA evolved since 2005 toward less seropositivity and lower blood inflammation but with more comorbidities. Milder erosive damage at baseline became evident only since 2011, mostly in seronegative patients. These changes at baseline, before any intervention, suggest ongoing secular trends that may favorably affect outcomes in patients with early RA.