Comparison of influenza and COVID-19 hospitalisations in British Columbia, Canada: a population-based study
Introduction We compared the population rate of COVID-19 and influenza hospitalisations by age, COVID-19 vaccine status and pandemic phase, which was lacking in other studies.Method We conducted a population-based study using hospital data from the province of British Columbia (population 5.3 millio...
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| Format: | Article |
| Language: | English |
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BMJ Publishing Group
2023-07-01
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| Series: | BMJ Open Respiratory Research |
| Online Access: | https://bmjopenrespres.bmj.com/content/10/1/e001567.full |
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| author | Hind Sbihi James Wilton Alexandra Choi Naveed Janjua Kate Smolina Solmaz Setayeshgar Moe Zandy |
| author_facet | Hind Sbihi James Wilton Alexandra Choi Naveed Janjua Kate Smolina Solmaz Setayeshgar Moe Zandy |
| author_sort | Hind Sbihi |
| collection | DOAJ |
| description | Introduction We compared the population rate of COVID-19 and influenza hospitalisations by age, COVID-19 vaccine status and pandemic phase, which was lacking in other studies.Method We conducted a population-based study using hospital data from the province of British Columbia (population 5.3 million) in Canada with universal healthcare coverage. We created two cohorts of COVID-19 hospitalisations based on date of admission: annual cohort (March 2020 to February 2021) and peak cohort (Omicron era; first 10 weeks of 2022). For comparison, we created influenza annual and peak cohorts using three historical periods years to capture varying severity and circulating strains: 2009/2010, 2015/2016 and 2016/2017. We estimated hospitalisation rates per 100 000 population.Results COVID-19 and influenza hospitalisation rates by age group were ‘J’ shaped. The population rate of COVID-19 hospital admissions in the annual cohort (mostly unvaccinated; public health restrictions in place) was significantly higher than influenza among individuals aged 30–69 years, and comparable to the severe influenza year (2016/2017) among 70+. In the peak COVID-19 cohort (mostly vaccinated; few restrictions in place), the hospitalisation rate was comparable with influenza 2016/2017 in all age groups, although rates among the unvaccinated population were still higher than influenza among 18+. Among people aged 5–17 years, COVID-19 hospitalisation rates were lower than/comparable to influenza years in both cohorts. The COVID-19 hospitalisation rate among 0–4 years old, during Omicron, was higher than influenza 2015/2016 and 2016/2017 and lower than 2009/2010 pandemic.Conclusions During first Omicron wave, COVID-19 hospitalisation rates were significantly higher than historical influenza hospitalisation rates for unvaccinated adults but were comparable to influenza for vaccinated adults. For children, in the context of high infection levels, hospitalisation rates for COVID-19 were lower than 2009/2010 H1N1 influenza and comparable (higher for 0–4) to non-pandemic years, regardless of the vaccine status. |
| format | Article |
| id | doaj-art-d6a972709a5748ef81f6efca80c40d3c |
| institution | DOAJ |
| issn | 2052-4439 |
| language | English |
| publishDate | 2023-07-01 |
| publisher | BMJ Publishing Group |
| record_format | Article |
| series | BMJ Open Respiratory Research |
| spelling | doaj-art-d6a972709a5748ef81f6efca80c40d3c2025-08-20T02:58:07ZengBMJ Publishing GroupBMJ Open Respiratory Research2052-44392023-07-0110110.1136/bmjresp-2022-001567Comparison of influenza and COVID-19 hospitalisations in British Columbia, Canada: a population-based studyHind Sbihi0James Wilton1Alexandra Choi2Naveed Janjua3Kate Smolina4Solmaz Setayeshgar5Moe Zandy6School of Population and Public Health, The University of British Columbia, Vancouver, British Columbia, Canada1University College London, Centre for Adolescent Rheumatology, London, United KingdomOffice of the Chief Medical Health Officer, Vancouver Coastal Health Authority, Vancouver, British Columbia, CanadaData and Analytic Services, BC Centre for Disease Control, Vancouver, British Columbia, CanadaBC Centre for Disease Control, Vancouver, British Columbia, CanadaData and Analytic Services, BC Centre for Disease Control, Vancouver, British Columbia, CanadaBC Centre for Disease Control, Vancouver, British Columbia, CanadaIntroduction We compared the population rate of COVID-19 and influenza hospitalisations by age, COVID-19 vaccine status and pandemic phase, which was lacking in other studies.Method We conducted a population-based study using hospital data from the province of British Columbia (population 5.3 million) in Canada with universal healthcare coverage. We created two cohorts of COVID-19 hospitalisations based on date of admission: annual cohort (March 2020 to February 2021) and peak cohort (Omicron era; first 10 weeks of 2022). For comparison, we created influenza annual and peak cohorts using three historical periods years to capture varying severity and circulating strains: 2009/2010, 2015/2016 and 2016/2017. We estimated hospitalisation rates per 100 000 population.Results COVID-19 and influenza hospitalisation rates by age group were ‘J’ shaped. The population rate of COVID-19 hospital admissions in the annual cohort (mostly unvaccinated; public health restrictions in place) was significantly higher than influenza among individuals aged 30–69 years, and comparable to the severe influenza year (2016/2017) among 70+. In the peak COVID-19 cohort (mostly vaccinated; few restrictions in place), the hospitalisation rate was comparable with influenza 2016/2017 in all age groups, although rates among the unvaccinated population were still higher than influenza among 18+. Among people aged 5–17 years, COVID-19 hospitalisation rates were lower than/comparable to influenza years in both cohorts. The COVID-19 hospitalisation rate among 0–4 years old, during Omicron, was higher than influenza 2015/2016 and 2016/2017 and lower than 2009/2010 pandemic.Conclusions During first Omicron wave, COVID-19 hospitalisation rates were significantly higher than historical influenza hospitalisation rates for unvaccinated adults but were comparable to influenza for vaccinated adults. For children, in the context of high infection levels, hospitalisation rates for COVID-19 were lower than 2009/2010 H1N1 influenza and comparable (higher for 0–4) to non-pandemic years, regardless of the vaccine status.https://bmjopenrespres.bmj.com/content/10/1/e001567.full |
| spellingShingle | Hind Sbihi James Wilton Alexandra Choi Naveed Janjua Kate Smolina Solmaz Setayeshgar Moe Zandy Comparison of influenza and COVID-19 hospitalisations in British Columbia, Canada: a population-based study BMJ Open Respiratory Research |
| title | Comparison of influenza and COVID-19 hospitalisations in British Columbia, Canada: a population-based study |
| title_full | Comparison of influenza and COVID-19 hospitalisations in British Columbia, Canada: a population-based study |
| title_fullStr | Comparison of influenza and COVID-19 hospitalisations in British Columbia, Canada: a population-based study |
| title_full_unstemmed | Comparison of influenza and COVID-19 hospitalisations in British Columbia, Canada: a population-based study |
| title_short | Comparison of influenza and COVID-19 hospitalisations in British Columbia, Canada: a population-based study |
| title_sort | comparison of influenza and covid 19 hospitalisations in british columbia canada a population based study |
| url | https://bmjopenrespres.bmj.com/content/10/1/e001567.full |
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