The Relationships, Employment, Autonomy, and Life Satisfaction (<scp>REALS</scp>) Measures for Autistic Adults and Adults With Other Intellectual and Developmental Disabilities: Psychometric Testing of the Self‐Report and Proxy Versions

Research and clinical work demonstrate that adults with intellectual and developmental disabilities (IDDs; including autistic adults and adults with other IDDs) struggle with key outcomes in adult life, including social relationships, employment, autonomy, and life satisfaction. However, few validated measures exist to measure these outcomes in adults with IDDs. The Relationships, Employment, Autonomy, and Life Satisfaction (REALS) Measures were created using methods developed by the Patient-Reported Outcomes Measurement Information System (PROMIS) to assess these outcomes. Large item pools were generated for the four domains, and, in field testing, 875 adults with IDDs (90% autistic; 18.4% with intellectual disability or a non-autism IDD) and 911 proxy reporters (caregivers; 79% autistic; 48.3% with intellectual disability or a non-autism IDD) completed 108 and 74 items, respectively, using response options capturing frequency, level of support needed, and satisfaction. The structure and item content of the REALS Measures were determined through an iterative process using both classical test theory and item response theory analyses. The final versions include 19 self-report and 14 proxy-report measures, with a range of 3 to 14 items each. The measures have excellent psychometric properties, high precision, and acceptable respondent burden. Thus, they are applicable for service provision, clinical, and research arenas for autistic adults and adults with other IDDs, though additional testing in IDD is warranted and evidence supporting self-report use in IDD is more limited.