Background incidence rates of hospitalisations and emergency department visits for thromboembolic and coagulation disorders in Ontario, Canada for COVID-19 vaccine safety assessment : a population-based retrospective observational study

Nasreen, Sharifa; Calzavara, Andrew J.; Sundaram, Maria E.; MacDonald, Shannon E.; Righolt, Christiaan H.; Pai, Menaka; Field, Thalia S.; Zhou, Lily W.; Wilson, Sarah E.; Kwong, Jeffrey C.

Background incidence rates of hospitalisations and emergency department visits for thromboembolic and coagulation disorders in Ontario, Canada for COVID-19 vaccine safety assessment : a population-based retrospective observational study

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dc.contributor.author: Nasreen, Sharifa; Calzavara, Andrew J.; Sundaram, Maria E.; MacDonald, Shannon E.; Righolt, Christiaan H.; Pai, Menaka; Field, Thalia S.; Zhou, Lily W.; Wilson, Sarah E.; Kwong, Jeffrey C.
dc.date.accessioned: 2025-02-10T18:49:29Z
dc.date.available: 2025-02-10T18:49:29Z
dc.date.issued: 2021-12-17
dc.description.abstract - en: Objective: The objective of this study was to estimate background rates of selected thromboembolic and coagulation disorders in Ontario, Canada. Design: Population-based retrospective observational study using linked health administrative databases. Records of hospitalisations and emergency department visits were searched to identify cases using International Statistical Classification of Diseases and Related Health Problems, 10th Revision, Canada diagnostic codes. Participants: All Ontario residents. Primary outcome measures: Incidence rates of ischaemic stroke, intracerebral haemorrhage, subarachnoid haemorrhage, deep vein thrombosis, pulmonary embolism, idiopathic thrombocytopaenia, disseminated intravascular coagulation and cerebral venous thrombosis during five prepandemic years (2015-2019) and 2020. Results: The average annual population was 14 million with 51% female. The mean annual rates per 100 000 population during 2015-2019 were 127.1 (95% CI 126.2 to 127.9) for ischaemic stroke, 22.0 (95% CI 21.6 to 22.3) for intracerebral haemorrhage, 9.4 (95% CI 9.2 to 9.7) for subarachnoid haemorrhage, 86.8 (95% CI 86.1 to 87.5) for deep vein thrombosis, 63.7 (95% CI 63.1 to 64.3) for pulmonary embolism, 6.1 (95% CI 5.9 to 6.3) for idiopathic thrombocytopaenia, 1.6 (95% CI 1.5 to 1.7) for disseminated intravascular coagulation, and 1.5 (95% CI 1.4 to 1.6) for cerebral venous thrombosis. Rates were lower in 2020 than during the prepandemic years for ischaemic stroke, deep vein thrombosis and idiopathic thrombocytopaenia. Rates were generally consistent over time, except for pulmonary embolism, which increased from 57.1 to 68.5 per 100 000 between 2015 and 2019. Rates were higher for females than males for subarachnoid haemorrhage, pulmonary embolism and cerebral venous thrombosis, and vice versa for ischaemic stroke and intracerebral haemorrhage. Rates increased with age for most of these conditions, but idiopathic thrombocytopaenia demonstrated a bimodal distribution with incidence peaks at 0-19 years and ≥60 years. Conclusions: Our estimated background rates help contextualise observed events of these potential adverse events of special interest and to detect potential safety signals related to COVID-19 vaccines.
dc.description.sponsorship: This work was supported by the Canadian Immunisation Research Network (CIRN) through a grant from the Public Health Agency of Canada and the Canadian Institutes of Health Research(CNF 151944). This study was also supported by ICES, which is funded by an annual grant from the Ontario Ministry of Health (MOH) and Ministry of Long term Care (MLTC) (Grant/award number: not applicable). JCK is supported by Clinician-Scientist Award from the University of Toronto Department of Family and Community Medicine.
dc.identifier.doi: https://doi.org/10.1136/bmjopen-2021-052019
dc.identifier.issn: 2044-6055
dc.identifier.pubmedID: 34921078
dc.identifier.uri: https://open-science.canada.ca/handle/123456789/3417
dc.language.iso: en
dc.publisher - en: BMJ
dc.rights - en: Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)
dc.rights - fr: Creative Commons Attribution-Pas d’Utilisation Commerciale 4.0 International (CC BY-NC 4.0)
dc.rights.uri - en: https://creativecommons.org/licenses/by-nc/4.0/
dc.rights.uri - fr: https://creativecommons.org/licenses/by-nc/4.0/deed.fr
dc.subject - en: Health; Epidemiology; Coronavirus diseases; Immunization
dc.subject - fr: Santé; Épidémiologie; Maladie à coronavirus; Immunisation
dc.subject.en - en: Health; Epidemiology; Coronavirus diseases; Immunization
dc.subject.fr - fr: Santé; Épidémiologie; Maladie à coronavirus; Immunisation
dc.title - en: Background incidence rates of hospitalisations and emergency department visits for thromboembolic and coagulation disorders in Ontario, Canada for COVID-19 vaccine safety assessment : a population-based retrospective observational study
dc.type - en: Article
dc.type - fr: Article
local.acceptedmanuscript.articlenum: e052019
local.article.journalissue: 12
local.article.journaltitle - en: BMJ Open
local.article.journalvolume: 11
local.pagination: 1-8
local.peerreview - en: Yes
local.peerreview - fr: Oui