Discordance between proxy-reported and observed assessment of functional ability of children with juvenile idiopathic arthritis.

OBJECTIVE: To determine the level of agreement between parents and clinicians in rating dysfunction in children with juvenile idiopathic arthritis (JIA).
METHODS: A parent of each patient completed the Italian version of the Childhood Health Assessment Questionnaire (CHAQ). Subsequently, an examiner assessed, in a specially equipped room, the child's performance of tasks as described by the CHAQ. Demographic and clinical variables were recorded for all patients.
RESULTS: Seventy consecutive JIA patients and their parents were included. The mean proxy-reported and observed CHAQ score was 0.64+/-0.53 and 0.47+/-0.62 respectively, the difference ranging from -1.75 to 1.5. There were 30 cases (43%) of agreement (difference < or =0.25 CHAQ units) between the parent's and clinician's ratings, whereas in 40 cases (57%) there was discordance (difference >0.25 CHAQ units). In 30 cases the parent rated the child's functional ability as worse than that observed by the clinician (i.e. the parent underestimated the child's function), whereas in 10 cases the parent rated the child's functional ability as better than that observed by the clinician (i.e. overestimated the child's function). Multivariate regression analysis showed that children's functional ability was overestimated by parents with increasing erythrocyte sedimentation rate and global articular severity score and underestimated with increasing level of pain. Among the functional areas of the CHAQ, the level of agreement was poorest in the areas of eating and hygiene and was best for activities.
CONCLUSIONS: Discordance between proxy-reported and observed functional ability was frequent in our patients with JIA. The children's functional ability was overestimated by parents as the severity of arthritis increased and underestimated as the level of pain increased.