Measurement invariance of the PROMIS emotional distress and subjective well-being domains among autistic and General Population adolescents.

Abstract

Purpose: Quality of life (QoL) is identified as a clinical and research priority by the autistic community. Researchers have the responsibility to ensure that instruments used to measure QoL do so reliably and accurately among autistic participants.

Methods: Our study evaluated measurement invariance of Emotional Distress (Depression, Anxiety, Anger, Psychological Stress) and Subjective Well-Being (Life Satisfaction, Positive Affect, and Meaning & Purpose) scales of the Patient-Reported Outcomes Measurement Information System (PROMIS) among groups of autistic (N=140, n per scale=132-140) and general population (N=1,224, n per scale=406-411) teenagers (14-17 years). These scales were included in the PROMIS Autism Battery-Lifespan, which uses PROMIS scales to measure QoL domains most relevant for autistic people.

Results: Multi-group confirmatory factor analyses using permutation tests demonstrated that Depression and Positive Affect scales exhibited scalar invariance between groups, indicating that scores can be meaningfully compared across autistic and general population teens. Anger and Psychological Stress scales demonstrated metric invariance between groups, indicating that these scales measure the same latent trait in both groups, but group comparisons are not supported.

Conclusion: We provide guidance as to how these scales can be used in psychometrically supported ways to capture constructs relevant for understanding QoL among autistic teens.