To evaluate outcome studies for childhood arthritides, we need to consider the heterogeneity of the disease, the criteria used to define the condition and how the population investigated was chosen. In this review, population- and hospital-based studies from the last 10 years were analysed. Due to the heterogeneity, continuing disease activity varied between 39 and 67% for all subgroups with the best prognosis for persistent oligoarthritis. Disability measured by CHAQ/HAQ showed that at least one-third of patients report some impact of the disease, but severe disability was rare. Many studies also report lower quality of life in patients compared with controls. Risk factors for disability were female sex, a polyarticular disease course and positive IgM rheumatoid factor.

In summary, juvenile idiopathic arthritis is both a self-limiting disease and a progressive disease, which creates disability and decreased quality of life. There seem to be differences in the quality of life and participation in society between nations, and further studies from different parts of the world are necessary. This research should include the perspective of patients and their families.