Background and objectives: Multi-item measures of inflammatory bowel disease (IBD) activity based on clinical, laboratory, and/or endoscopic variables do not take into consideration the impact on the patients' emotional aspects and adaptation to the disease. The aim of the present study was to evaluate concordance between parent and child ratings of health-related quality of life on the IMPACT-III questionnaire in children with IBD.
Methods: The IMPACT-III questionnaire was used to measure quality of life in 27 patients (mean age 14.2 ± 3 years, 40% girls) and one of their parents (82% mothers). Most of the patients had inactive disease at the time of the study. Differences between parent-proxy ratings and child ratings on the IMPACT-III were compared via paired-samples t tests, intraclass correlation coefficients, and standardized difference scores.
Results: Parent-proxy and patient ratings were similar on total IMPACT-III and its related domains (bowel symptoms, systemic symptoms, social functioning, body image, treatment/interventions), except that significant differences on emotional functioning ratings were found (P = 0.003). Intraclass correlation coefficients showed medium-to-large effect sizes (range 0.52-0.88) and standardized difference scores showed varying degrees of bias depending on the domain measured (range -0.64 to 0.32).
Conclusions: Parents served as a good proxy for quality-of-life ratings in this population of pediatric patients with IBD. The degree of concordance between parent and child scores, however, varied, as observed in the present study in which parents underreported their child's health-related quality of life on the IMPACT-III emotional functioning domain.