Sarah E Wilson1, Laura C Rosella2, Jun Wang3, Ariane Renaud4, Nicole Le Saux5, Natasha S Crowcroft6, Shalini Desai7, Tara Harris4, Shelly Bolotin8, Jonathan Gubbay9, Shelley L Deeks8. 1. Public Health Ontario, Toronto, Ontario, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada; Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada. Electronic address: sarah.wilson@oahpp.ca. 2. Public Health Ontario, Toronto, Ontario, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada; Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada. 3. Public Health Ontario, Toronto, Ontario, Canada; Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada. 4. Public Health Ontario, Toronto, Ontario, Canada. 5. Division of Infectious Disease, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada; Department of Pediatrics, University of Ottawa, Ontario, Canada. 6. Public Health Ontario, Toronto, Ontario, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada; Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada. 7. Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada. 8. Public Health Ontario, Toronto, Ontario, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada. 9. Public Health Ontario, Toronto, Ontario, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada; Department of Pediatrics, The Hospital for Sick Children, Toronto, Ontario, Canada; Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada.
Abstract
BACKGROUND: Ontario implemented a publicly-funded rotavirus (RV) immunization program in 2011. Our objectives were to evaluate its impact on hospitalizations and emergency department (ED) visits for acute gastroenteritis (AGE) five years after implementation. METHODS: We performed a population-based longitudinal retrospective cohort study to identify hospitalizations and ED visits for RV-AGE and overall AGE in all age groups using ICD-10 codes between August 1, 2005 and March 31, 2016. A negative binomial regression model that included the effect of time was used to calculate rates, rate ratios (RRs) and 95% confidence intervals (CIs) for AGE before and after the program's implementation, after adjusting for age, seasonality and secular trends. We examined the seasonality of RV-AGE hospitalizations among children under five before and after the program and explored its equity impact. RESULTS: Following program implementation, RV-AGE hospitalizations and ED visits among children under five years declined by 76% (RR 0.24, 95% CI 0.20-0.28) and 68% (RR 0.32, 95% CI 0.21-0.50), respectively. In addition, hospitalizations and ED visits for overall AGE declined by 38% (RR 0.62, 95% CI 0.59-0.65) and 26% (RR 0.74, 95% CI 0.73-0.76), respectively, among children under age five. Significant reductions in both outcomes were also found across a range of age-strata. In the pre-program period, the mean monthly hospitalization rate for RV-AGE among children residing in the most marginalized neighbourhoods was 33% higher than those residing in the least marginalized (RR 1.33, 95% CI 1.17-1.52), this disparity was not evident in the program period (RR 0.95, 95% CI 0.69-1.32). We found no evidence of a seasonal shift in rotavirus pediatric hospitalizations. INTERPRETATION: The introduction of routine infant rotavirus immunization has had a substantial population impact in Ontario. Our study confirms herd effects and suggests the program may have reduced previous inequities in the burden of pediatric rotavirus hospitalizations. Crown
BACKGROUND: Ontario implemented a publicly-funded rotavirus (RV) immunization program in 2011. Our objectives were to evaluate its impact on hospitalizations and emergency department (ED) visits for acute gastroenteritis (AGE) five years after implementation. METHODS: We performed a population-based longitudinal retrospective cohort study to identify hospitalizations and ED visits for RV-AGE and overall AGE in all age groups using ICD-10 codes between August 1, 2005 and March 31, 2016. A negative binomial regression model that included the effect of time was used to calculate rates, rate ratios (RRs) and 95% confidence intervals (CIs) for AGE before and after the program's implementation, after adjusting for age, seasonality and secular trends. We examined the seasonality of RV-AGE hospitalizations among children under five before and after the program and explored its equity impact. RESULTS: Following program implementation, RV-AGE hospitalizations and ED visits among children under five years declined by 76% (RR 0.24, 95% CI 0.20-0.28) and 68% (RR 0.32, 95% CI 0.21-0.50), respectively. In addition, hospitalizations and ED visits for overall AGE declined by 38% (RR 0.62, 95% CI 0.59-0.65) and 26% (RR 0.74, 95% CI 0.73-0.76), respectively, among children under age five. Significant reductions in both outcomes were also found across a range of age-strata. In the pre-program period, the mean monthly hospitalization rate for RV-AGE among children residing in the most marginalized neighbourhoods was 33% higher than those residing in the least marginalized (RR 1.33, 95% CI 1.17-1.52), this disparity was not evident in the program period (RR 0.95, 95% CI 0.69-1.32). We found no evidence of a seasonal shift in rotavirus pediatric hospitalizations. INTERPRETATION: The introduction of routine infant rotavirus immunization has had a substantial population impact in Ontario. Our study confirms herd effects and suggests the program may have reduced previous inequities in the burden of pediatric rotavirus hospitalizations. Crown