Parent IMPACT-III: Development and Validation of an IBD-Specific Health-Related Quality of Life Measure

OBJECTIVES: The present study aimed to validate the parent-proxy IMPACT-III (IMPACT-III-P) in a sample of youth diagnosed with inflammatory bowel disease (IBD). Parent-proxy report measures are standard for pediatric psychosocial assessment, and the IMPACT-III-P will provide a more comprehensive representation of HRQOL. Reliability and validity analyses were conducted. METHODS: Parents (N = 50) of youth 8 to 17 years with IBD reported on their child's HRQOL (IMPACT-III-P and PedsQL-4.0) and depression (BASC-2); youth reported on their HRQOL (child IMPACT-III), pain interference (PROMIS Pain Interference), and disease symptoms; and physicians completed measures of disease activity. RESULTS: Criterion validity was established as the IMPACT-III-P was strongly, positively associated with the PedsQL (r = 0.59, P < 0.001). Convergent validity was supported as higher IMPACT-III-P scores were associated with less pain interference (r = -0.41, P < 0.01) and lower depression (r = -0.41, P < 0.01). Discriminant validity was partially supported, as higher IMPACT-III-P scores were associated with lower child-reported symptoms (r = -0.41, P < 0.01), but scores did not differ based on inactive, mild, or moderate/severe disease activity groups as rated by physicians. Internal consistency, parent-child agreement, and item-level analyses revealed strong reliability. CONCLUSIONS: The IMPACT-III-P demonstrated strong validity and reliability. Parents and children had similar reports of HRQOL, with parents rating child HRQOL slightly lower. Findings support the use of the IMPACT-III-P for youth 8 to 17 years old to use in accordance with the child IMPACT-III to provide valuable information regarding HRQOL in youth with IBD.