Milder disease trajectory among COVID-19 patients hospitalised with the SARS-CoV-2 Omicron variant compared with the Delta variant in Norway
This article has been Reviewed by the following groups
Listed in
- Evaluated articles (ScreenIT)
Abstract
Using individual-level national registry data, we conducted a cohort study to estimate differences in the length of hospital stay, and risk of admission to an intensive care unit and in-hospital death among patients infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant, compared with patients infected with Delta variant in Norway. We included 409 (38%) patients infected with Omicron and 666 (62%) infected with Delta who were hospitalised with coronavirus disease 2019 (COVID-19) as the main cause of hospitalisation between 6 December 2021 and 6 February 2022. Omicron patients had a 48% lower risk of intensive care admission (adjusted hazard ratios (aHR): 0.52, 95% confidence interval (CI): 0.34–0.80) and a 56% lower risk of in-hospital death (aHR: 0.44, 95%CI: 0.24–0.79) compared with Delta patients. Omicron patients had a shorter length of stay (with or without ICU stay) compared with Delta patients in the age groups from 18 to 79 years and those who had at least completed their primary vaccination. This supports growing evidence of reduced disease severity among hospitalised Omicron patients compared with Delta patients.
Article activity feed
-
-
SciScore for 10.1101/2022.03.10.22272196: (What is this?)
Please note, not all rigor criteria are appropriate for all manuscripts.
Table 1: Rigor
Ethics IRB: Ethics: Ethical approval was granted by Regional Committees for Medical Research Ethics - Southeast Norway, reference number 249509. Sex as a biological variable not detected. Randomization not detected. Blinding not detected. Power Analysis not detected. Table 2: Resources
No key resources detected.
Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).
Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:One limitation with our study is that a higher proportion of patients admitted to ICU had known variant (see supplement A, part 3). …
SciScore for 10.1101/2022.03.10.22272196: (What is this?)
Please note, not all rigor criteria are appropriate for all manuscripts.
Table 1: Rigor
Ethics IRB: Ethics: Ethical approval was granted by Regional Committees for Medical Research Ethics - Southeast Norway, reference number 249509. Sex as a biological variable not detected. Randomization not detected. Blinding not detected. Power Analysis not detected. Table 2: Resources
No key resources detected.
Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).
Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:One limitation with our study is that a higher proportion of patients admitted to ICU had known variant (see supplement A, part 3). Given the increased risk of ICU admission for Delta patients, we may have oversampled severely ill Delta patients, which may cause us to slightly overestimate the reduction in our outcomes for Omicron patients. Another important limitation is that we could not distinguish sublineage BA.1 and BA.2 for all Omicron patients. In Norway BA.2 has gradually begun to outcompete BA.1 (16). However, up to the end of the study period, BA.1 was still the dominant circulating Omicron sublineage, and our results were robust when we excluded 57 patients known to be infected with BA.2 (see supplement A, part 2.4). Further studies are needed to investigate whether disease severity differs between Omicron sublineages. Evidence of lower disease severity among hospitalised Omicron patients in Norway and elsewhere is encouraging in the ongoing response to the COVID-19 pandemic. Analyses of circulating variants in a local context are important for informing decision-making on control measures and hospital capacity planning in different settings.
Results from TrialIdentifier: No clinical trial numbers were referenced.
Results from Barzooka: We did not find any issues relating to the usage of bar graphs.
Results from JetFighter: We did not find any issues relating to colormaps.
Results from rtransparent:- Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
- Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
- No protocol registration statement was detected.
Results from scite Reference Check: We found no unreliable references.
-
