Measurement of health status, functional status, and quality of life in children with juvenile idiopathic arthritis: clinical science for the pediatrician.

Several groups have undertaken research on health status, functional status, and quality of life in the pediatric rheumatic diseases, particularly juvenile idiopathic arthritis (JIA) and juvenile rheumatoid arthritis. This article highlights the principles involved in this type of measurement, discusses the measures that have been developed for JIA, and describes the outcomes determined from recent retrospective and prospective longitudinal outcome studies. These studies suggest that although there has been improvement in overall outcomes, significant numbers of individuals persist with active disease into adulthood and have significant damage, reduced functional ability, and disability.