Abstract
Social relationships are a key component of quality of life, a high-priority outcome for autistic people, and family relationships are critical in adolescence. The PROMIS Family Relationships scale has been well validated for use with the general population, but psychometric validation in the autistic population is lacking. This study investigated measurement invariance of the PROMIS Family Relationships among autistic and general population adolescents. The scale demonstrated scalar invariance between the groups, providing evidence that it measures the same construct equivalently and scores can be meaningfully compared between groups. With a well-validated self-report measure, researchers can ask autistic teens directly about their experiences of their family relationships, rather than relying solely on parent proxy report.