On Apr. 16, 1992, a controlled trial of showed low-dose methotrexate to be effective in resistant Juvenile rheumatoid arthritis (JRA). The researchers concluded that methotrexate given weekly in low doses is an effective treatment for children with resistant juvenile rheumatoid arthritis, and at least in the short term this regimen is safe.

JRA is the most common rheumatic condition of childhood, with an annual incidence of about 1.4 cases per 10,000 children under the age of 16 years in the United States, and a prevalence of roughly 1 per 1000.