Over the past four decades, a number of studies have evaluated the long-term outcome of juvenile idiopathic arthritis (JIA) and some of them have also attempted to identify early prognostic factors. Altogether, the available data indicate that JIA is not a benign disease because a considerable number of patients still enter adulthood with persistently active disease and a significant proportion of them may develop severe physical disability. Among the different disease categories, the long-term outcome is best in persistent oligoarthritis and worst in RF-positive polyarthritis; the outcome of systemic arthritis is widely variable, perhaps reflecting the heterogeneity of this JIA subtype. The comparison of earlier studies with those published in the last decade shows a decline in the frequency of patients with severe physical disability over the years; however, the proportion of patients who enter adulthood with active disease does not seem to be diminished. A recent study of 310 children with long-standing JIA (disease duration > 5 years) seen between September 2002 and December 2006 showed that at follow-up evaluation only 21.8% met the criteria for inactive disease, and less than 50% met the definition of minimal disease activity. 19.2% had moderate to severe physical disability and 3.6% were in Steinbrocker class III–IV. Approximately 10% had major impairment in health-related quality of life (HRQL). A total of 34.2% had damage in >1 joint or joint group and 26.1% showed extraarticular damage. Of the 125 patients who underwent a wrist radiograph, 35.2% had significant structural damage. 8.7% of patients had growth retardation. Altogether, these data suggest that patients currently followed in Western pediatric rheumatology centers have, on average, a low level of disease activity, little or no physical disability, and a satisfactory HRQOL. However, a sizable proportion of patients have persistently active disease, impaired function, and damage. Although there is considerable data on prognostic factors in JIA, prediction of long-term outcome early after disease presentation is still difficult because comparisons among studies are hindered for a variety of reasons. Thus, while a considerable body of data is accumulating, the definition of the longterm outcome of JIA remains imperfect. To increase the comparability of future analyses and to obtain generalizable information on the prognosis of JIA and its prediction, a great deal of effort should be directed toward standardizing the study design and the measurement of predictors and outcomes. Furthermore, the impact of recent therapeutic advances should be taken into account.

Disclosure of Interest None Declared