Autism diagnostic aid (ADA) tool for use in adults with intellectual disability: development, face and content validation

Abstract

Purpose Individuals with intellectual disability have an increased predisposition to other co-morbid physical health conditions, mental illness and neurodevelopmental conditions including autism spectrum condition. There are challenges in diagnosing autism in adults with intellectual disability, and these are often attributes to the complexities in symptoms. The purpose of this paper is to describe the development of the autism diagnostic aid (ADA) tool and face and content validation of its properties. Design/methodology/approach The ADA tool was developed following a detailed scoping exercise which included literature reviews, observations and discussion with wider multi-disciplinary team members. A face and content validation after consultation with eight experts who are trained and routinely perform assessments for autism spectrum disorders. The experts also have expertise in working with individuals with intellectual disability. Findings The experts agreed that the ADA tool is appropriate to the targeted construct and assessment objectives as a diagnostic aid in the assessment of autism in adults with intellectual disability. They also determined that the content of ADA tool was valid for its use as a diagnostic aid in the diagnosis of adults with intellectual disability. Research limitations/implications The ADA tool was considered a valid tool from the expert’s perspective. It was identified to have a good face and content validity. To the best of the authors’ knowledge, the ADA is first of its kind tool, developed specifically to aid clinicians with autism assessments in adults with intellectual disability. Practical implications This tool could potentially help with timely assessment and help with providing appropriate intervention but would require further exploration. Originality/value To the best of the authors’ knowledge, this is the first of its kind tool for the assessment of autism in adults with intellectual disability.