Complications Following SARS-CoV-2 Infection in Victoria, Australia: A Record Linkage Study

Background: SARS-CoV-2 infection can induce significant pathologies including neurological, cardiac and vascular disease events. We assessed strength of association between SARS-CoV-2 infection and several key respiratory and non-respiratory complications in Victoria, Australia. Methods: Record linkage was used to assemble all laboratory-confirmed COVID-19 cases notified 1 January 2020–31 May 2021 with corresponding hospitalisation  episodes to 30 September 2021. Hospitalisation  rates and reasons for hospitalisation  among cases was assessed using a cohort study design. A self-controlled case series was used to assess strength of association between SARS-CoV-2 infection and several outcomes in the first 90 days following COVID-19 illness onset. Incident rate ratios (IRR) and 95% confidence intervals were calculated comparing risk in the post-exposure period with a baseline period prior to SARS-CoV-2 infection. Findings: There were 20,594 COVID-19 cases, with 2,992 (14·53%) related hospitalisation s. In the 90-days following COVID-19 illness onset, elevated risks were observed for myocarditis and pericarditis (IRR: 14·76, 95% confidence interval 3·19–68·30); thrombocytopenia (IRR: 7·38, 4·36–12·50), pulmonary embolism (IRR: 6·37; 3·55–11·43), acute myocardial infarction (IRR: 3·89, 2·59–5·84) and cerebral infarction and non-ischemic stroke (IRR: 2·31, 1·37–3·90). Interpretation: There is a strong association between SARS-CoV-2 infection and risk of several complications highlighting the value of COVID-19 pandemic mitigation measures such as vaccination. Improved awareness of these risks may support early diagnosis and management of patients with a past history of SARS-CoV-2 infection, and contribute to a greater understanding of the public health burden of COVID-19. Funding Information: No funding was provided for this study. Declaration of Interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/disclosure-of-interest/ and declare: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work. Ethics Approval Statement: Study approvals were obtained from the Victorian Government Department of Health Research Ethics Committee (reference: LNR/76271/DHHS-2021-272262(v2)) and from each data custodian responsible for each informational asset used. The study was also registered with the Monash University Human Research Ethics Committee (reference: 30071).