Understanding and measuring caregiver-reported quality of life among minimally verbal autistic children with intellectual disability

To address the dearth of literature on outcomes for autistic individuals with significant intellectual disability, researchers require validated measures to use in research. This study examined the psychometric properties of PROMIS quality-of-life caregiver-proxy scales included in the PROMIS Autism Battery–Lifespan among autistic children who are minimally verbal and with intellectual disability (MVID). We examined basic psychometric properties of the PROMIS caregiver-proxy scales and tested the scales for measurement invariance between groups of autistic children who are minimally verbal with intellectual disability and those without signficant intellectuatl disability ( N = 448). We also descriptively examined feedback from caregivers regarding the appropriateness of the questions to capture meaningful outcomes for their autistic children who are minimally verbal with intellectual disability. Results indicated that some PROMIS caregiver-proxy scales (Anger, Positive Affect, and Life Satisfaction) exhibited strong psychometric evidence and content validity, but many other scales either did not demonstrate measurement invariance between groups or included a high proportion of items endorsed by caregivers as not applicable for their minimally verbal autistic child. Our findings emphasize the need for continued work developing appropriate measures for capturing meaningful outcomes among minimally verbal autistic people with significant intellectual disability.