To compare the efficacy of therapy with a combination of disease-modifying antirheumatic drugs (DMARDs) versus therapy with a single DMARD in the prevention of work disability in patients with early rheumatoid arthritis (RA). In the Finnish Rheumatoid Arthritis Combination Therapy trial, 195 patients with recent-onset RA were randomly assigned to receive either combination therapy with DMARDs (sulfasalazine, methotrexate, hydroxychloroquine) plus prednisolone or single therapy with a DMARD with or without prednisolone. After 2 years, the drug treatment strategy was no longer restricted. At baseline, 162 patients (80 in the combination-treatment group and 82 in the single-treatment group) were still working or at least available for work. After 5 years of followup, data on all sick leave and retirement were obtained from social insurance registers or case records. The main outcome for each patient was the cumulative duration of all sick leaves and RA-related disability pensions, divided by the observation period during which the patient was not retired because of another disease or because of age. The cumulative duration of work disability per patient-observation year was significantly lower in those randomized to combination therapy than in those randomized to single therapy: median 12.4 days (interquartile range [IQR] 0-54) versus 32.2 days (IQR 6-293) (P = 0.008, sex- and age-adjusted P = 0.009). This was mainly due to the difference in sick leaves (i.e., work disability periods