Omicron (BA.1) SARS-CoV-2 variant is associated with reduced risk of hospitalization and length of stay compared with Delta (B.1.617.2)

Article activity feed

1. 

   PREreview

   Feb 16, 2022

   This Zenodo record is a permanently preserved version of a PREreview. You can view the complete PREreview at https://prereview.org/reviews/6098001.

   Main Claim & Relevance:

   In this preprint, the authors conducted a cohort study of individuals diagnosed with SARS-CoV-2 infection. They found that infection with the Omicron variant was associated with a 75% risk reduction of hospitalization, an 86% risk reduction of death, and a 4 day reduction in the length of hospital stays compared to infection with the Delta variant.

    

   Are the findings strong, reliable, potentially informative, not informative, or misleading?

   The findings of this study are reliable. The inclusion of 15,978 individuals adjusted for sex, age, previous infection, and vaccination status allows for a strongly powered and representative analysis of the course of …

   This Zenodo record is a permanently preserved version of a PREreview. You can view the complete PREreview at https://prereview.org/reviews/6098001.

   Main Claim & Relevance:

   In this preprint, the authors conducted a cohort study of individuals diagnosed with SARS-CoV-2 infection. They found that infection with the Omicron variant was associated with a 75% risk reduction of hospitalization, an 86% risk reduction of death, and a 4 day reduction in the length of hospital stays compared to infection with the Delta variant.

    

   Are the findings strong, reliable, potentially informative, not informative, or misleading?

   The findings of this study are reliable. The inclusion of 15,978 individuals adjusted for sex, age, previous infection, and vaccination status allows for a strongly powered and representative analysis of the course of SARS-CoV-2 infection. These findings could have been further improved by correcting for additional characteristics of the participants such as socioeconomic status, which can be an important factor in patient health outcomes.

    

   How might these ideas presented by the main claims further knowledge of the COVID-19 Pandemic?

   There has been an abundant amount of speculation and media attention directed towards Omicron and how it compares to previous variants of concern. The findings of this preprint may be useful in deciding the best course of care to provide to a patient, and contribute to the overall body of knowledge regarding the current SARS-CoV-2 variants.

    

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2. 

   ScreenIT

   Jan 28, 2022

   SciScore for 10.1101/2022.01.20.22269406: (What is this?)

   Please note, not all rigor criteria are appropriate for all manuscripts.

   Table 1: Rigor

   Ethics

   IRB: The research on genomic epidemiology of SARS-COV-2 received the clearance of the Ethics Committee of INSA on March 30, 2021.

   Sex as a biological variable

   Where h(t|X) is the hazard at the time t of the outcome hospitalization conditional on covariates X (Omicron, age group, sex, previous infection and vaccine status), h0(t) is the baseline hazard for the outcome, exp (β1 Omicron) the hazard ratio for the outcome being infected with Omicron variant compared with Delta, exp (β2 age group) are the hazard ratios for the outcome being 80 years or older, 65 years old to 80 compared with being 16 to 65 years old, exp (β3 sex) the hazard ratio for the outcome being a female compared with being …

   SciScore for 10.1101/2022.01.20.22269406: (What is this?)

   Please note, not all rigor criteria are appropriate for all manuscripts.

   Table 1: Rigor

   Ethics	IRB: The research on genomic epidemiology of SARS-COV-2 received the clearance of the Ethics Committee of INSA on March 30, 2021.
   Sex as a biological variable	Where h(t|X) is the hazard at the time t of the outcome hospitalization conditional on covariates X (Omicron, age group, sex, previous infection and vaccine status), h0(t) is the baseline hazard for the outcome, exp (β1 Omicron) the hazard ratio for the outcome being infected with Omicron variant compared with Delta, exp (β2 age group) are the hazard ratios for the outcome being 80 years or older, 65 years old to 80 compared with being 16 to 65 years old, exp (β3 sex) the hazard ratio for the outcome being a female compared with being male, exp (β4 previous infection) is the hazard ratio for the outcome of primary infection compared with having a previous infection, exp (β5 vaccination status) is the hazard ratio for the outcome having incomplete, complete, or complete plus booster compared with unvaccinated, ε is the error term.
   Randomization	Secondly, we use Whole-Genome Sequencing (WGS) data provided by the National Health Institute (INSA) that routinely performs sequencing on random samples notified to SINAVE.
   Blinding	not detected.
   Power Analysis	not detected.

   Table 2: Resources

   Software and Algorithms
   Sentences	Resources
   We used information from a nationwide network group of laboratories (UNILABS, ABC and CVP) that performs RT-PCR tests for SARS-CoV-2 using Thermofisher TaqPath assay, targeting three regions of the SARS-CoV-2 genome: ORF1ab, N and S genes.	Thermofisher TaqPath suggested: None
   Secondly, we use Whole-Genome Sequencing (WGS) data provided by the National Health Institute (INSA) that routinely performs sequencing on random samples notified to SINAVE.	WGS suggested: None
   We used a nearest-neighbor algorithm with the “Matchit”(23) CRAN package.	CRAN suggested: (CRAN, RRID:SCR_003005)

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   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).

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   Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:

   Our study also had limitations; we did not have access to previous comorbidities, which could be an unaccounted confounder. Also, the study participants with Omicron and Delta had baseline differences that could influence the risk of hospitalization; although this was accounted for in the adjusted models, residual confounding could still be present. The adjusted risk increased the HR by 66%, hence the protection effect of omicron could be partially explained by age, sex, previous infection, and vaccination status. Finally, we did not account for correcting hazard ratio estimates in unvaccinated individuals for under ascertainment of past infection status; that method was shown in the English study to decrease the risk reduction. Hence, we could be overestimating the risk reduction.

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   Results from TrialIdentifier: No clinical trial numbers were referenced.

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   Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

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   Results from JetFighter: We did not find any issues relating to colormaps.

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   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.

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   Results from scite Reference Check: We found no unreliable references.

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   Read the original source
3. 

   Version published to 10.1101/2022.01.20.22269406 on medRxiv

   Jan 23, 2022