Subtypes of avoidant/restrictive food intake disorder in children and adolescents: a latent class analysis

Background The Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5) describes three primary avoidant/restrictive food intake disorder (ARFID) subtypes including sensory sensitivity, lack of interest in food or eating, and fear of aversive consequences. Studies exploring these subtypes have yielded varying results. We used latent class analysis (LCA) based on the psychopathology of ARFID in a sample of children and adolescents to empirically identify classes. Methods We carried out a surveillance study of ARFID in collaboration with the British Paediatric Surveillance Unit (BPSU) and the Child and Adolescent Psychiatry Surveillance System (CAPSS) in the United Kingdom and the Republic of Ireland from 1st of March 2021 to 31st of March 2022. Paediatricians and child and adolescent psychiatrists were contacted monthly to report newly diagnosed cases of ARFID electronically and complete a detailed clinical questionnaire. Cases aged 5-18 years were included. LCA was performed specifying 1-6 classes and likelihood-based tests for model selection. The Bayesian Information Criterion (BIC), the Akaike Information Criterion (AIC) and the Sample-Size Adjusted BIC were used to determine the most parsimonious model. Analysis of variance (ANOVA) and chi 2 tests were used to compare the characteristics of the identified classes. A multinomial logistic regression (MLR) was performed to investigate predicting factors for the latent classes. Findings We identified 319 children and adolescents with ARFID. LCA revealed four distinct classes which were labelled as Fear subtype, Lack of Interest subtype, Sensory subtype, and Combined subtype. The probability of being classified as these were 7.2% (n = 23), 25.1% (n = 80), 29.5% (n = 94) and 38.2% (n = 122), respectively. Age at diagnosis, sex, weight loss, distress associated with eating, and autism spectrum disorder diagnosis were identified as predictors of class membership. Interpretation LCA identified four different classes in a sample of children and adolescents with ARFID. The Combined Subtype, a mixed presentation was the most common. The other three classes resembled the subtypes described in the literature. Clinicians should be aware of these different presentations of ARFID as they may benefit from different clinical interventions.