The factor structure and validity of a diagnostic interview for avoidant/restrictive food intake disorder in a sample of children, adolescents, and young adults

Objective: There is a paucity of validated diagnostic interviews for avoidant/restrictive food intake disorder (ARFID) to aid identification and classification of cases for both clinical and research purposes. To evaluate the factor structure, construct validity, and criterion validity of the Pica ARFID and Rumination Disorder Interview (PARDI; ARFID module), we administered the PARDI to 129 children and adolescents ages 9-23 years (M = 16.1) with ARFID (n = 84), subclinical ARFID (n = 11), and healthy controls (n = 34).

Method: We used exploratory factor analysis to examine the factor structure of the PARDI in children, adolescents, and young adults with an ARFID diagnosis, the Kruskal-Wallis analysis of variance and Spearman correlations to test the construct validity of the measure, and non-parametric receiver operating characteristic curves to evaluate the criterion validity of the PARDI.

Results: Exploratory factor analysis yielded a 3-factor structure: (1) concern about aversive consequences of eating, (2) low appetite/low interest in food, and (3) sensory sensitivity. Participants with ARFID demonstrated significantly higher levels of sensory sensitivity, low appetite/low-food interest, and concern about aversive consequences of eating symptoms relative to control participants. The construct validity for each PARDI subscale was supported and clinical cutoffs for the low appetite/low interest in food (1.1) and sensory sensitivity subscales (0.6) were established.

Discussion: These data present evidence for the factor structure and validity of the PARDI diagnostic interview for diagnosing ARFID in children, adolescents, and young adults, supporting the use of this tool to facilitate ARFID clinical assessment and research.

Public significance: Due to the paucity of validated diagnostic interviews for avoidant/restrictive food intake disorder (ARFID), we evaluated the factor structure and validity of the Pica ARFID and Rumination Disorder Interview (ARFID module). Findings suggest that the interview assesses 3 components of ARFID: concern about aversive consequences of eating, low-appetite, and sensory sensitivity, and that clinical threshold scores on the latter two subscales can be used to advance ARFID assessment.