Social disparities and the COVID-19, influenza, and RSV 'tripledemic' in Ontario, Canada: A population-based study

We examined inequalities in weekly hospitalization rates related to COVID-19, influenza, and respiratory syncytial virus based on neighbourhood-level material deprivation, neighbourhood-level ethno-racial diversity, rurality, and sex. Hospitalization rates were measured as the weekly number of hospitalizations per 10 000 people. Local regression models were used to fit observed weekly hospitalization rates within each study year and each population subgroup, and statistical significance of between-subgroup differences in peak hospitalization rate was assessed based on the overlap of 95% confidence intervals. We also provided comparisons of pre-pandemic (July 2017-June 2020) versus post-pandemic (July 2020-June 2023) trends. More materially deprived neighbourhoods showed up to a 2.5-times increase in peak weekly hospitalization rates compared to less materially deprived neighbourhoods. Peak hospitalization rates were up to 2.3-times higher among more versus less diverse neighbourhoods. Some age groups showed peak hospitalization rates up to 2.8-times higher among urban residents. Peak hospitalization rates were up to 1.3-times higher in younger males versus younger females and up to 1.6-times higher in older females versus older males. Variations due to neighbourhood-level material deprivation, neighbourhood-level ethno-racial diversity, rurality, and sex should be considered when designing and implementing public health policies aiming to reduce respiratory virus burden.