The DESIR (Devenir des spondylarthropathies indifférenciées récentes) cohort is a rather successful 10-year follow-up study of 708 patients with early inflammatory back pain lasting > 3 months and < 3 years, and recruited within 26 months in 25 centers in France. Patients were followed up every 6 months during the first 2 years and then once every year.1
