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An international observational study to assess the impact of the Omicron variant emergence on the clinical epidemiology of COVID-19 in hospitalised patients

Gonçalves, Bronner P and Hall, Matthew and Jassat, Waasila and Balan, Valeria and Murthy, Srinivas and Kartsonaki, Christiana and Semple, Malcolm G and Rojek, Amanda and Baruch, Joaquín and Reyes, Luis Felipe and Dasgupta, Abhishek and Dunning, Jake and Citarella, Barbara Wanjiru and Pritchard, Mark and Martín-Quiros, Alejandro and Sili, Uluhan and Baillie, J Kenneth and Aryal, Diptesh and Arabi, Yaseen M and Rashan, Aasiyah and Angheben, Andrea and Caoili, Janice and Carrier, François Martin and Harrison, Ewen M and Gómez-Junyent, Joan and Figueiredo-Mello, Claudia and Joshua Douglas, James and Mat Nor, Mohd Basri and Chow, Yock Ping and Wong, Xin Ci and Bertagnolio, Silvia and Thwin, Soe Soe and Streinu-Cercel, Anca and Salazar, Leonardo and Rishu, Asgar and Rangappa, Rajavardhan and Ong, David SY and Hashmi, Madiha and Carson, Gail and Diaz, Janet and Fowler, Rob and Kraemer, Moritz UG and Wils, Evert-Jan and Horby, Peter and Merson, Laura and Olliaro, Piero L (2022) An international observational study to assess the impact of the Omicron variant emergence on the clinical epidemiology of COVID-19 in hospitalised patients. elife. pp. 1-42. E-ISSN 2050-084X

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Background: Whilst timely clinical characterisation of infections caused by novel SARS-CoV-2 vari- ants is necessary for evidence-based policy response, individual-level data on infecting variants are typically only available for a minority of patients and settings. Methods: Here, we propose an innovative approach to study changes in COVID-19 hospital presen- tation and outcomes after the Omicron variant emergence using publicly available population-level data on variant relative frequency to infer SARS-CoV-2 variants likely responsible for clinical cases. We apply this method to data collected by a large international clinical consortium before and after the emergence of the Omicron variant in different countries. Results: Our analysis, that includes more than 100,000 patients from 28 countries, suggests that in many settings patients hospitalised with Omicron variant infection less often presented with commonly reported symptoms compared to patients infected with pre-Omicron variants. Patients with COVID-19 admitted to hospital after Omicron variant emergence had lower mortality compared to patients admitted during the period when Omicron variant was responsible for only a minority of infections (odds ratio in a mixed-effects logistic regression adjusted for likely confounders, 0.67 [95% confidence interval 0.61–0.75]). Qualitatively similar findings were observed in sensitivity analyses with different assumptions on population-level Omicron variant relative frequencies, and in analyses using available individual-level data on infecting variant for a subset of the study population. Conclusions: Although clinical studies with matching viral genomic information should remain a priority, our approach combining publicly available data on variant frequency and a multi-country clinical characterisation dataset with more than 100,000 records allowed analysis of data from a wide range of settings and novel insights on real-world heterogeneity of COVID-19 presentation and clinical outcome.

Item Type: Article (Journal)
Uncontrolled Keywords: Omicron variant, COVID-19, observational study, clinical epidemiology
Subjects: R Medicine > RC Internal medicine > RC82 Medical Emergencies, Critical Care, Intensive Care, First Aid
Kulliyyahs/Centres/Divisions/Institutes (Can select more than one option. Press CONTROL button): Kulliyyah of Medicine > Department of Anaesthesiology & Intensive Care
Depositing User: Dr. Mohd Basri Mat Nor
Date Deposited: 14 Oct 2022 08:23
Last Modified: 14 Oct 2022 08:23
URI: http://irep.iium.edu.my/id/eprint/100591

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