Geographic variation and neighbourhood correlates of mental health-related hospitalizations and emergency department visits in children and youth during the COVID-19 pandemic: a population-based study.

Background: The COVID-19 pandemic was associated with increased mental health-related hospitalizations and emergency department (ED) visits in children and youth. However, population-based studies examining geographic variation in, and neighbourhood correlates of, acute mental health service use in this population during the pandemic are lacking. Methods: We conducted a population-based study examining geographic variation in and neighbourhood correlates of mental health-related hospitalizations and ED visits among Ontario children and youth. We used hot spot analyses to visualize geographic variation in service use before (March 2017 to February 2020) and during (March 2020 to July 2021) the pandemic. We used spatial regression models to estimate unstandardized and standardized coefficients of the association between neighbourhood characteristics and acute mental health service use. Results: Mental health-related hospitalization and ED visit rates were highest in rural and northern Ontario. The variables most strongly associated with hospitalization rates within the same neighbourhood were neighbourhood income and family size. A one standard deviation (SD) increase in income was associated with a 0.50 (95% CI: -0.56 to -0.43) SD decrease in hospitalization rates, while a one SD increase in family size was associated with a 0.35 (95% CI: 0.29-0.42) SD increase in hospitalization rates. Additionally, increases of one SD in neighbourhood income, the proportion of the population speaking neither English nor French, and remoteness were associated with respective increases in the SD of hospitalization rates of in adjacent areas. Neighbourhood income and remoteness were strongly associated with ED visit rates, with each standard deviation increase in income associated with a 0.52 (95% CI: -0.57 to -0.47) standard deviation decrease in ED visits while each standard deviation increase in remoteness was associated with a 0.29 (95% CI: 0.21-0.37) standard deviation increase in ED visit rates. Conclusion: Geographic location and neighbourhood socioeconomic and demographic factors influenced acute mental health service use among children and youth during the pandemic. These findings highlight the need for targeted social interventions that address neighbourhood disparities and bolster mental health services in vulnerable regions, particularly in preparation for future large-scale disruptions.