Does adapting a self-report instrument to improve its cognitive accessibility for people with intellectual disability result in a better measure? − A cognitive interview study

Background and aims

We investigated whether improving the cognitive accessibility of a widely used self-report measure leads to better understanding and more accurate answers in a sample of adults with mild intellectual disability and borderline intellectual functioning.

Methods and procedures

We undertook a series of cognitive interviews before and after adaptation of the instructions and selected items of an existing self-report measure of adaptive functioning. Interview results and participant feedback were supplemented with quantitative comparisons between participant and carer scores.

Outcomes and results

Adaptation based on participant experiences and preferences combined with evidence-informed guidelines improved understanding and accuracy. Self-report and carer-report scores showed greater convergence after adaptation; this occurred because people with intellectual disabilities appeared to understand the self-report measure more effectively.

Conclusions and implications

The results show that adaptation of the self-report instrument to suit the needs and preferences of people with mild intellectual disability or borderline intellectual functioning leads to a more accessible measure and more reliable and valid results. Results also highlight the importance of complementing proxy reports with a first-person perspective in assessment as clients and informants may differ in their assessment of behavior and skills.