Understanding Caregiver-Reported Outcomes in Clinical Trials for Children with Intellectual Disability: A Scoping Review

Abstract

Objective: To examine how caregiver-reported outcomes are incorporated in clinical trials involving children and adolescents with intellectual disability (ID), including alignment with regulatory guidance about observer- versus proxy-reporting. Methods: We conducted a scoping review, using a systematic search strategy and screening citations in duplicate to identify interventional trials in children and adolescents with ID, published 2019-2024, that included caregiver-reported outcomes. We extracted trial characteristics and outcome measurement instruments (OMIs) from eligible reports, analyzing OMIs used as primary endpoints. Results: From 8,167 citations, we identified 88 trials, 38 of which included a caregiver-reported primary outcome; 20 unique OMIs were primary endpoints. Caregiver characteristics, training, and OMI psychometric properties were infrequently reported. OMIs were not easily classifiable as observer- versus proxy-reported based on instructions and item wording. Conclusions: Clearer reporting of caregiver-reported OMIs in pediatric ID trials, including instrument characteristics and measurement details, is needed to improve interpretability and alignment with guidance.