A New Domain Structure for the IMPACT-III Health-related Quality of life Tool for Pediatric Inflammatory Bowel Disease.

Abstract

The IMPACT-III measures health-related quality of life (HRQOL) in pediatric patients with Inflammatory Bowel Disease (IBD). The original IMPACT domain structure was developed based on expert opinion and was not psychometrically validated. This study developed a new domain structure based on the current IMPACT version. Baseline data from 3 prospectively collected datasets of children and adolescents with IBD was used. Exploratory, then confirmatory factor analyses were carried out to develop a new domain structure. Internal consistency (Cronbach alpha) and construct validity with PROMIS measures (Pearson correlations, and Independent Mann-Whitney U-tests) were examined. Data from the IBD Partners dataset alone (n = 374; 47% girls, mean age = 13.4 ± 2.5 years, median disease duration = 2.5 years, 75% were in remission, with a range of self-reported disease activity) was used to validate the new 4-domain IMPACT-III model. The final domain structure was parsimonious, with factor loadings for individual items ranging from 0.39 to 0.80, and internal consistency for domains from 0.75 to 0.95. The new IMPACT-III domains include: General well-being, Social Functioning, Emotional functioning, and Body Image. IMPACT-III total and domain scores were significantly lower (all P < 0.001) for participants with high (>50) versus low (<50) PROMIS anxiety, depression, fatigue, and pain T-scores; conversely IMPACT-III scores were higher for participants with higher peer-relations PROMIS T-scores. This valid and reliable IMPACT-III domain structure should be used to capture pediatric self-reported HRQOL, which will help to understand the management of IBD from the perspective of patients.