4 The Impact of the COVID-19 Pandemic on Number and Severity of New Diagnoses of Restrictive Eating Disorders During Prolonged Lockdown in Ontario, Canada

Abstract Background The coronavirus disease 2019 (COVID-19) pandemic has had a disproportionate impact on the well-being of adolescents and young adults. Worldwide, eating disorder (ED) experts have observed worsening symptoms in youth with pre-existing EDs and an escalation in the number of new cases compared to prior years. Disruption of routine, work and school closures, as well as social isolation are potential contributing factors. The Canadian province of Ontario (specifically the most highly populated cities) experienced one of the most prolonged lock downs worldwide with approximately 20 weeks of face-to-face school closure and/or restriction to virtual learning. Objectives We sought to better understand the impact of COVID-19 on new pediatric ED presentations, patient characteristics and hospital admissions in a tertiary care Children’s Hospital. Design/Methods We completed a retrospective chart review of patients presenting for new ED assessments at a single centre pediatric ED program within a tertiary care children’s hospital between January 1st, 2015 and June 1st 2021. Patients aged 9-18 years old with a new diagnosis of Anorexia Nervosa (AN) restrictive type or binge/purge type or Other Specified Feeding and Eating Disorder (OSFED) - Atypical Anorexia Nervosa (AAN) were included. Demographic and clinical variables for pre and post pandemic were analyzed using Chi-Square and T-Tests. Interrupted time series regression was used to examine pre-pandemic and post-pandemic monthly summary data over time. Results Overall, 425 youth were newly diagnosed with AN or AAN (N=329 pre-pandemic, N=96 pandemic) during the study period (Jan 1 2015 – December 31 2020). Average age was 14.7 years (SD 1.8, range 8.1 – 17.9). Most youth were diagnosed with DSM-5 AN-restrictive type (65.6%). The number of new diagnoses of AN and AAN during the pandemic more than doubled when compared to pre-pandemic years. In the 5-year period preceding the pandemic, mean number of newly diagnosed cases was 5.1/month (ßcoeff=0.043, p=0.33), increasing to 10.6/month (p=