Trends in the Observed Versus Expected Incidence of Eating Disorders Before, During, and After the COVID-19 Pandemic: A National Patient Registry Study.

objectiveThis study investigated post-pandemic trends in the incidence of eating disorders (EDs) by comparing the annual observed incidence from January 1st, 2020, to December 31st, 2023, to the expected incidence based on pre-pandemic trends (2010-2019).

methodPrimary and auxiliary ICD-10 diagnoses of new-onset ED cases were retrieved from the Norwegian Patient Registry which is a national register covering all specialized healthcare services in Norway. Incidence rates (IRs) per 100,000 were stratified by age, sex, and diagnosis: anorexia nervosa (AN; F50.0 + 50.1), bulimia nervosa (BN; F50.2 + 50.3), and other EDs (F50.4-50.9). To assess the impact of the COVID-19 pandemic, linear regression models were used to estimate the annual excess incidence of EDs between 2020 and 2023.

resultsIRs for EDs peaked in 2021, with the overall rate for females being 45.5% higher than expected in 2021 before declining to an excess of 19.4% in 2023. The highest IRs were observed in females aged 15-19, followed by females aged 10-14 and 20-24 years. In 2021, the IR for females aged 15-19 was 64.7% higher than expected before declining sharply to 10.9% in 2023, whereas IRs for ages 10-14 and 20-24 remained approximately 30% higher than expected. Increases were particularly pronounced for AN, while the incidence of BN remained comparatively low, tracking with observed pre-pandemic declines.

conclusionsNew-onset ED cases peaked in 2021, then declined in 2022 and 2023, despite remaining higher than expected based on 10 years of pre-pandemic data. Future research should continue to monitor trends in incidence, and community-based studies are necessary for replication.