PURPOSE: The range of impairments in children with neurodisability (ND) complicates data collection, yet individualising materials and procedures could enable more children to self-report. This study introduces the Cognitive Accessibility Tracking Questionnaire (CATQ), designed to monitor changes enhancing accessibility ("adaptations") in interview-administered patient-reported outcome measures (PROMs). The CATQ is used in a longitudinal study of mental health and participation in children with ND investigating adaptation use and its utility in assessing the risk of bias introduced by these adaptations.

MATERIALS AND METHODS: The 13-item CATQ was developed with experts in ND and augmentative and alternative communication. Predictors of PROM adaptations were analysed using linear regression; the overall change was tested with a t-test and item-specific agreement with Cohen's weighted kappa and proportion of agreement.

RESULTS: Six interviewers conducted 69 interviews, interviewing 43 children once or twice. Common adaptations included explaining/replacing concepts (56.5% of interviews), exemplifying (60.9%), or repeating questions/instructions (50.7%). Child age, seizure history, verbal communication abilities, adaptive behaviour, and interviewer identity predicted adaptation use. Adaptation use did not differ between the two data collection points, 13 months apart.

CONCLUSION: The CATQ enhances methodological rigor by tracking adaptations and facilitating risk-of-bias-assessment by analysing adaptation changes and factors affecting their use.