Trend in the age mortality structure during the COVID-19 pandemic

Introduction. The COVID-19 pandemic, caused by a novel SARS-CoV-2 coronavirus infection, lasted just over three years. Its end was announced in early May 2023. According to official data, the pandemic claimed 6.9 million lives worldwide, but it is believed that at least 20 million people were victims. The first wave of the pandemic was caused by a virus that spread from China. The virus mainly kills representatives of older age groups of the population and is characterized by a high degree of mutagenicity, which contributes to the emergence of new strains of the virus. The most aggressive and established in the population new strains of the virus spread and gave rise to the second wave of the pandemic, which turned out to be the longest. The third wave was caused by the most aggressive strain, spreading from India, and caused the greatest number of deaths.

Aim of the study was to identify the extent to which changes in the virus itself affected the gender and age mortality structure during the three waves of the COVID-19 pandemic observed between 2020 and 2021.

Materials and methods. The method of single factor analysis of variance was applied. The study was based on the data of the Operational Headquarters under the Government of Samara region, which were published daily with the indication of gender, age, and cause of each death.

Results. The analysis confirmed the influence of the virus variability factor on the age mortality structure at the significance level of p<0.05. Comparison of the diagrams of the shares of the selected age segments in the mortality of men and women in each of the pandemic waves clearly showed how the gender and age mortality structure changed. The result of the analysis of variance showed that the changes occurring in the virus itself, although not as significant, affected the mortality pattern, with male mortality being more affected than female mortality.

Conclusion. The result of the analysis of variance showed changes occurring in the virus itself to have an impact on the mortality structure, and on male mortality to a greater extent than on female mortality.

Compliance with ethical standards. This study does not require the conclusion of a biomedical ethics committee or other documents.

Contributions:
Kuznetsova R.S. — concept and design of the study, statistical data processing, analysis and interpretation of data, writing and editing the text;
Lazareva N.V. — concept and design of the study, writing and editing the text;
Kudinova G.E. — literature search, material processing, data analysis and interpretation;
Rozenberg A.G. – literature search, material processing, writing and editing text.
All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.

Conflict of interest. The authors declare no conflict of interest.

Acknowledgement. The work was performed within the framework of the State assignment: Reg. No. 1021060107217–0-1.6.19.

Received: May 2, 2024 / Accepted: June 19, 2024 / Published: July 17, 2024