Prevalence and short-term outcome of juvenile idiopathic arthritis: a population-based study in Estonia

To study the point prevalence of juvenile idiopathic arthritis (JIA) in children in Estonia on December 31, 2000. To examine the short-term clinical outcome of the disease.

Identification of patients diagnosed with JIA between 1995-2000. Prospective follow-up of new cases diagnosed between 1998-2000 for two years. Retrospective analysis of the medical records of patients diagnosed between 1995-1997. The study was population-based.

One hundred and ninety-seven (197) patients fulfilled the study criteria. On December 31, 2000, the point prevalence of JIA was 83.7 (95% CI: 72.4; 95.8) per 100 000 children aged 0-15 years, 90.7 (95% CI: 74.1; 108.9) for girls and 77.1 (95% CI: 62.2; 93.5) for boys. Prevalence was the highest among 11-15 year-old girls (132; 95% CI: 100.7; 167.4) and the lowest in 0-3 year-old girls (9.6; 95% CI: 1.2; 26.7). For 44 patients (22.3%), the disease was inactive after 2 years since the onset of the disease. For 76 patients (38.6%). the disease was active or stable after 2 years.

This is the first population-based study on the prevalence and outcome of JIA in Estonia in which the new ILAR criteria have been used. A longer follow-up of JIA patients is needed to have a better overview of the course of the disease. Good cooperation between family doctors and specialists is crucial for diagnosing JIA as early as possible.