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Surveillance Open Access
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Abstract

Background

It sparked considerable attention from international media when Denmark lifted restrictions against COVID-19 in February 2022 amidst widespread transmission of the new SARS-CoV-2 Omicron variant and a steep rise in reported COVID-19 mortality based on the 30-day COVID-19 death count.

Aim

Our aim was to investigate how coincidental infections affected COVID-19 mortality estimates following the introduction of the Omicron variant in late 2021.

Methods

We compared the 30-day COVID-19 death count with the observed mortality using three alternative mortality estimation methods; (i) a mathematical model to correct the 30-day COVID-19 death count for coincidental deaths, (ii) the Causes of Death Registry (CDR) and (iii) all-cause excess mortality.

Results

There was a substantial peak in the 30-day COVID-19 death count following the emergence of the Omicron variant in late 2021. However, there was also a substantial change in the proportion of coincidental deaths, increasing from 10–20% to around 40% of the recorded COVID-19 deaths. The high number of 30-day COVID-19 deaths was not reflected in the number of COVID-19 deaths in the CDR and the all-cause excess mortality surveillance.

Conclusion

Our analysis showed a distinct change in the mortality pattern following the introduction of Omicron in late 2021 with a markedly higher proportion of people estimated to have died rather than COVID-19 compared with mortality patterns observed earlier in the COVID-19 pandemic. Our findings highlight the importance of incorporating alternative mortality surveillance methods to more correctly estimate the burden of COVID-19 as the pandemic continues to evolve.

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/content/10.2807/1560-7917.ES.2023.28.3.2200547
2023-01-19
2023-02-04
http://instance.metastore.ingenta.com/content/10.2807/1560-7917.ES.2023.28.3.2200547
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References

  1. Kumar S, Thambiraja TS, Karuppanan K, Subramaniam G. Omicron and Delta variant of SARS-CoV-2: A comparative computational study of spike protein. J Med Virol. 2022;94(4):1641-9.  https://doi.org/10.1002/jmv.27526  PMID: 34914115 
  2. Wolter N, Jassat W, Walaza S, Welch R, Moultrie H, Groome M, et al. Early assessment of the clinical severity of the SARS-CoV-2 omicron variant in South Africa: a data linkage study. Lancet. 2022;399(10323):437-46.  https://doi.org/10.1016/S0140-6736(22)00017-4  PMID: 35065011 
  3. Lewnard JA, Hong VX, Patel MM, Kahn R, Lipsitch M, Tartof SY. Clinical outcomes associated with SARS-CoV-2 Omicron (B.1.1.529) variant and BA.1/BA.1.1 or BA.2 subvariant infection in Southern California. Nat Med. 2022;28(9):1933-43.  https://doi.org/10.1038/s41591-022-01887-z  PMID: 35675841 
  4. Dole N. COVID-19 cases rise every day in Denmark, but the country is confident it can live without restrictions for now. ABC News. 2022. Available from: https://www.abc.net.au/news/2022-02-13/denmark-has-taken-living-with-covid-to-a-whole-new-level/100812736
  5. Craig E. Danish health chiefs dismiss doom-mongering claims that Covid deaths and hospitalisations are soaring since country became first to ditch its final virus restrictions. Daily Mail Online. 2022. Available from: https://www.dailymail.co.uk/news/article-10516251/Denmark-steps-thwart-spread-fake-news-country-drop-restrictions.html
  6. Mathieu E, Ritchie H, Rodés-Guirao L, Appel C, Giattino C, Hasell J, et al. Coronavirus (COVID-19) deaths. OurWorldinData. [Accessed: 15 Mar 2022]. Available from: https://ourworldindata.org/covid-deaths
  7. Li L, Wong JY, Wu P, Bond HS, Lau EHY, Sullivan SG, et al. Heterogeneity in estimates of the impact of influenza on population mortality: a systematic review. Am J Epidemiol. 2018;187(2):378-88.  https://doi.org/10.1093/aje/kwx270  PMID: 28679157 
  8. Paget J, Spreeuwenberg P, Charu V, Taylor RJ, Iuliano AD, Bresee J, et al. Global mortality associated with seasonal influenza epidemics: New burden estimates and predictors from the GLaMOR Project. J Glob Health. 2019;9(2):020421.  https://doi.org/10.7189/jogh.09.020421  PMID: 31673337 
  9. Iacobucci G. Covid-19: unravelling the conundrum of omicron and deaths. BMJ. 2022;376:o254.  https://doi.org/10.1136/bmj.o254  PMID: 35091392 
  10. World Health Organization (WHO). International guidelines for certification and classification (coding) of COVID-19 as cause of death. Geneva: WHO; 2020. Available from: https://www.who.int/publications/m/item/international-guidelines-for-certification-and-classification-(coding)-of-covid-19-as-cause-of-death
  11. Bodilsen J, Leth S, Nielsen SL, Holler JG, Benfield T, Omland LH. Positive predictive value of ICD-10 diagnosis codes for COVID-19. Clin Epidemiol. 2021;13:367-72.  https://doi.org/10.2147/CLEP.S309840  PMID: 34079379 
  12. Mazick A, Gergonne B, Nielsen J, Wuillaume F, Virtanen MJ, Fouillet A, et al. Excess mortality among the elderly in 12 European countries, February and March 2012. Euro Surveill. 2012;17(14):20138.  https://doi.org/10.2807/ese.17.14.20138-en  PMID: 22516003 
  13. Coronavirus Resource Center. Mortality analyses. Baltimore: Johns Hopkins University. [Accessed: 15 Mar 2022]. Available from: https://coronavirus.jhu.edu/data/mortality
  14. Schwab N, Nienhold R, Henkel M, Baschong A, Graber A, Frank A, et al. COVID-19 autopsies reveal underreporting of SARS-CoV-2 infection and scarcity of co-infections. Front Med (Lausanne). 2022;9:868954.  https://doi.org/10.3389/fmed.2022.868954  PMID: 35492342 
  15. Simonsen L, Spreeuwenberg P, Lustig R, Taylor RJ, Fleming DM, Kroneman M, et al. Global mortality estimates for the 2009 influenza pandemic from the GLaMOR project: a modeling study. PloS Med. 2013;10(11):e1001558.  https://doi.org/10.1371/journal.pmed.1001558  PMID: 24302890 
  16. Coronavirus (COVID-19) latest insights: deaths. Newport: Office for National Statistics. [Accessed: 8 Jun 2022]. Available from: https://www.ons.gov.uk/peoplepopulationandcommunity/healthandsocialcare/conditionsanddiseases/articles/coronaviruscovid19latestinsights/deaths#covid-19-and-flu-deaths
  17. World Health Organization (WHO). Classification of Omicron. (B.1.1.529): SARS-CoV-2 variant of concern. Geneva: WHO: 2021. Available from: https://www.who.int/news/item/26-11-2021-classification-of-omicron-(b.1.1.529)-sars-cov-2-variant-of-concern
  18. Madhi SA, Kwatra G, Myers JE, Jassat W, Dhar N, Mukendi CK, et al. Population immunity and Covid-19 severity with Omicron variant in South Africa. N Engl J Med. 2022;386(14):1314-26.  https://doi.org/10.1056/NEJMoa2119658  PMID: 35196424 
  19. EuroMOMO. EuroMOMO pooled estimates are approaching normal levels. EuroMOMO Bulletin, week 22, 2022. Copenhagen: EuroMOMO; 2022. Available from: https://www.euromomo.eu/bulletins/2022-22
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