Ability of the childhood health assessment questionnaire in predicting outcome of patients with juvenile idiopathic arthritis

Introduction. Juvenile idiopathic arthritis (JIA) is a chronic inflammatory disease associated with decreased functional capacity and potentially long-term consequences. The establishment of early prognostic factors could help in the prevention of joint damage and improve the quality of life in children with JIA. Objective. The aim of the study was to evaluate the functional status of children with JIA by using the Childhood Health Assessment Questionnaire (CHAQ) and to assess its ability in predicting the outcome of the disease. Methods. The study included 87 patients, average age 14 years, under follow-up on the average of 3.7 years. Parents/ patients over 12 years completed CHAQ based on which disability index (DI) was calculated. Disease outcome was determined according to the preliminary criteria for clinical remission. Results. At the end of the follow-up period, functional ability improved significantly (0.541 vs. 0.398; p<0.05). During the study, in 52.8% of patients treatment with biologic drug etanercept was introduced. CHAQ showed good predictive validity when a baseline DI was compared with disease outcome at the final examination (F=18.349; p<0.001). Using the patients with normal functional ability (DI=0) as the reference group, in patients with moderate and more severe functional disability the odds ratio for the disease to be active at the end of the follow-up period (DI≥0.6) was 4.6 (p=0.044). Conclusion. Functional ability of patients with JIA significantly improved during the follow-up period owing to the efficient therapy. The questionnaire for the assessment of the functional status is a simple tool, with good ability to predict disease outcome, and should thus be used in everyday clinical practice with the aim to identify patients with poor prognosis