Validation of the Italian version of the Stanford Childhood Health Assessment Questionnaire for measuring functional status in children with chronic arthritis

The Stanford Health Assessment Questionnaire developed by Singh et al. to measure functional status in children with chronic arthritis (CHAQ) was translated into Italian (I-CHAQ), with minor modifications to obtain cross-cultural equivalence. This version was evaluated in a series of 96 patients with juvenile rheumatoid arthritis (JRA), both males and females ranging in age from 3 to 19 years (mean age 9.9 years). All three onset subtypes and all four classes of disability were represented in the sample. The questionnaire was filled in by the parents if the children were less than 8 years of age (23 cases), and by the children themselves in all other cases; a health professional was always present to provide assistance. As expected, JRA patients with a systemic or polyarticular disease onset had higher scores than those with a pauciarticular onset, and there were statistically significant dfferences in disability index values between patients from different Steinbrocker functional classes. The instrument showed good reproducibility in a test-retest over a two-week period, a high correlation between the child and parent scores, excellent internal reliability, and good convergent and discriminant validity.