Development of a self-report functional status index for juvenile rheumatoid arthritis

There are few functional indices available for juvenile rheumatoid arthritis (JRA). Our goal was to develop a reliable, valid and responsive self-report physical functional status index for individuals with JRA, ages 8-18 years.

Activity (item) generation by interview of children, parents, teachers, clinicians yielded 280 items. Categories of self-care, domestic, mobility, school, and extracurricular were chosen by clinicians. Twelve clinicians sorted the items into categories. Item reduction was by these clinicians who rated items for common problems in JRA, importance of performance, and potential for change.

Ninety-nine items were retained. A separate section was designed for respondents to identify their priority activities. Content validity of the questionnaire, the Juvenile Arthritis Self-Report Index (JASI), was evaluated by 17 different clinicians. One item was added and none eliminated; all rated the index as a credible functional measure for JRA.

The JASI has been rigorously developed, and has demonstrated content validity. Index validation is being completed.