Screening for Avoidant/Restrictive Food Intake Disorder Symptoms Among Autistic Adults: Measurement Invariance With a Comparison General Sample

Research suggests a higher prevalence of avoidant/restrictive food intake disorder (ARFID) in autistic people across the lifespan compared to the general population. However, ARFID symptoms in autistic people may be misattributed to core autistic traits and gastrointestinal symptoms that often co-occur with autism. This diagnostic overshadowing could lead to the under-recognition and under-treatment of modifiable symptoms of psychopathology in autistic people. Validating ARFID symptom measures in this population is essential to screening for ARFID and tracking treatment outcomes in this population. Multigroup confirmatory factor analysis was used to evaluate the equivalence of the factor structure, factor loadings, and item intercepts of the Nine-Item ARFID Screen (NIAS) between a sample of autistic adults (n = 248) who self-disclosed their diagnosis and a comparison general sample (n = 398). There was support for strong measurement invariance (configural, metric, and scalar) on the NIAS. Autistic adults scored significantly higher on each of the three subscales: selective eating (d = 0.54), appetite impairment (d = 0.27), and fear-driven avoidance of eating (d = 0.37). The NIAS is a valid instrument for measuring ARFID symptomatology in autistic adults. Autistic adults experience elevated symptomatology across all three ARFID eating restrictions. Future research should address whether evidence-based ARFID treatments are efficacious for autistic adults or need to be modified.