A chronological review of COVID-19 case fatality rate and its secular trend and investigation of all-cause mortality and hospitalization during the Delta and Omicron waves in the United States: a retrospective cohort study

Frontiers in Public Health

Public Health

Shu-Bai Hsu¹  Jing-Xing Li²  Pei-Lun Liao³  James Cheng-Chung Wei⁴  Chih-Jung Yeh⁵ 

[1] College of Medicine, China Medical University, Taichung, Taiwan;Department of Nursing, China Medical University Hospital, Taichung, Taiwan;Department of Internal Medicine, Taipei Veterans General Hospital, Taipei, Taiwan;School of Medicine, China Medical University, Taichung, Taiwan;Graduate Institute of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University, Taipei, Taiwan;Department of Medical Research, Chung Shan Medical University Hospital, Taichung, Taiwan;Department of Nursing, Chung Shan Medical University, Taichung, Taiwan;Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan;Department of Allergy, Immunology & Rheumatology, Chung Shan Medical University Hospital, Taichung, Taiwan;Graduate Institute of Integrated Medicine, China Medical University, Taichung, Taiwan;Department of Public Health, Chung Shan Medical University, Taichung, Taiwan;

关键词: coronavirus disease 2019;    COVID-19;    case fatality rate;    CFR;    mortality trends;    SARS-CoV-2;   

DOI  :  10.3389/fpubh.2023.1143650

 received in 2023-01-13, accepted in 2023-08-14,  发布年份 2023

来源: Frontiers

【 摘 要 】

IntroductionCoronavirus disease 2019 (COVID-19) has caused more than 690 million deaths worldwide. Different results concerning the death rates of the Delta and Omicron variants have been recorded. We aimed to assess the secular trend of case fatality rate (CFR), identify risk factors associated with mortality following COVID-19 diagnosis, and investigate the risks of mortality and hospitalization during Delta and Omicron waves in the United States.MethodsThis study assessed 2,857,925 individuals diagnosed with COVID-19 in the United States from January 2020, to June 2022. The inclusion criterion was the presence of COVID-19 diagnostic codes in electronic medical record or a positive laboratory test of the SARS-CoV-2. Statistical analysis was bifurcated into two components, longitudinal analysis and comparative analysis. To assess the discrepancies in hospitalization and mortality rates for COVID-19, we identified the prevailing periods for the Delta and Omicron variants.ResultsLongitudinal analysis demonstrated four sharp surges in the number of deaths and CFR. The CFR was persistently higher in males and older age. The CFR of Black and White remained higher than Asians since January 2022. In comparative analysis, the adjusted hazard ratios for all-cause mortality and hospitalization were higher in Delta wave compared to the Omicron wave. Risk of all-cause mortality was found to be greater 14–30 days after a COVID-19 diagnosis, while the likelihood of hospitalization was higher in the first 14 days following a COVID-19 diagnosis in Delta wave compared with Omicron wave. Kaplan–Meier analysis revealed the cumulative probability of mortality was approximately 2-fold on day 30 in Delta than in Omicron cases (log-rank p < 0.001). The mortality risk ratio between the Delta and Omicron variants was 1.671 (95% Cl 1.615–1.729, log-rank p < 0.001). Delta also had a significantly increased mortality risk over Omicron in all age groups. The CFR of people aged above 80 years was extremely high as 17.33%.ConclusionMale sex and age seemed to be strong and independent risk factors of mortality in COVID-19. The Delta variant appears to cause more hospitalization and death than the Omicron variant.

【 授权许可】

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Copyright © 2023 Li, Liao, Wei, Hsu and Yeh.