Incidence of avoidant/restrictive food intake food intake disorder in children and adolescents across the UK and Ireland: a BPSU and CAPSS surveillance study

Objective: We aimed to estimate the incidence of avoidant/restrictive food intake disorder (ARFID) in children and adolescents (CA) presenting to secondary care in the United Kingdom (UK) and Republic of Ireland (ROI). Design: An observational surveillance study, using the British Paediatric Surveillance Unit (BPSU) and the Child and Adolescent Psychiatry Surveillance System (CAPSS), involving monthly electronic reporting by consultant paediatricians and CA psychiatrists between 1st March 2021 and 31st March 2022 and outcomes at one-year follow-up. Setting: The UK and ROI. Participants: Clinician-reported data on children and young people aged 5–17 (inclusive) in contact with paediatric services or CA mental health services for a new diagnosis of ARFID. Primary outcome measures: Annual incidence rates (IRs) estimated as confirmed new cases per 100 000 population at risk. Results: 319 newly diagnosed cases of ARFID were reported over the 13-month surveillance period and assessed as eligible for inclusion. The mean age of the sample was 11.2 years (SD = 3.8). The sample consisted of 145 females (45.5%). Most cases were of White British ethnicity (71.2%). The observed IR (IR0) in the UK was 2.79 per 100 000 CA (95% CI 2.48-3.13), with a higher IRo in males (2.98 per 100 000 CA [95% CI 2.55-3.49]) than in females (2.58 per 100 000 CA [95% CI 2.18-3.07]). Comorbidity was common in this sample with anxiety and autism spectrum disorder. At follow-up, 54.8% of cases had improved according to clinicians’ clinical impression. Conclusions: We conducted the first study reporting estimates of incidence of ARFID in CA in the UK and ROI presenting to secondary care. Our finding that ARFID is a disorder of relatively low incidence in CA should help inform service planning and resource allocation, as well as the development of evidence-based interventions.