Objectives: The French Society of Rheumatology initiated a large national multicenter, longitudinal and prospective cohort, the so-called "ESPOIR cohort study" in order to set up databases to allow various investigations on diagnosis, prognostic markers, epidemiology, pathogenesis and medico-economic factors in the field of early arthritis and rheumatoid arthritis.
Methods: Patients were recruited if they had undifferentiated arthritis or rheumatoid arthritis, of less than 6 months disease duration and if they were DMARD and steroids naïve. Patients have then to be followed every 6 months during the first 2 years then every year during at least 10 years. Clinical, biological, radiographic and medico-economic databases have been constituted to fit in the different objectives of the project and more than 20 scientific studies have already been accepted by the scientific committee.
Results: 813 patients were included (76.75% were female). The mean age was 48.07+/-12.55 years. The mean delay from the onset of symptoms to referral to the rheumatologist was 74.8+/-76.6 days. Baseline swollen and tender joint counts were 7.19+/-5.37 and 8.43+/-7.01; DAS28 score was 5.11+/-1.31. CRP was abnormal in 38.9% of the patients; 44.2%, 45.8% and 38.8% had respectively IgM rheumatoid factor (RF), IgA RF and anti-CCP antibodies. HLA DRB1*01 or 04 genes were found in 56.7% of them. Finally, 22% of these patients had erosions on hand or feet at baseline.