Treatment outcomes for avoidant/restrictive food intake disorder and anorexia nervosa among children and adolescents in higher levels of care

<i>Background:</i> There is large variability in the way that outcomes are measured for avoidant/restrictive food intake disorder (ARFID), with many studies focusing solely on weight gain or using measures that are not designed or validated to assess ARFID symptoms, such as the widely used Eating Disorders Examination-Questionnaire (EDE-Q).<i>Objective:</i> The current study compared treatment outcomes for children/adolescents with ARFID to children/adolescents with anorexia nervosa-restricting subtype (AN-R) on weight variables (% of expected body weight (%EBW)), ARFID symptoms as measured using the Eating Disorders in Youth-Questionnaire (EDY-Q), and eating disorder (ED) symptoms (as measured using the EDE-Q). Scores for both groups of patients on each measure were examined to preliminarily determine the appropriateness of each measure for each diagnosis.<i>Method:</i> Participants were 220 children/adolescents aged 9 to 17 receiving treatment at a large multisite treatment facility between November 2020 and June 2023. Self-report questionnaires were completed at intake and discharge, and weight was recorded throughout treatment.<i>Results:</i> EDY-Q, EDE-Q, and %EBW scores changed significantly (<i>p</i> < 0.001) from admission to discharge for both groups of patients. Effect sizes for changes in EDY-Q were similarly large for patients with AN-R (<i>d</i> = 0.91) and ARFID (<i>d</i> = 0.83). Effect sizes for changes in EDE-Q were large for patients with AN-R (<i>d</i> = 0.79) and small-to-medium for patients with ARFID (<i>d</i> = 0.47).<i>Conclusions:</i> Results suggest that the EDY-Q may be assessing symptoms present in both patients with ARFID and patients with AN-R. The study's findings suggest that the EDE-Q is not an appropriate measure for assessing outcomes among patients with ARFID.