Publication date: Feb 05, 2025
Studies on COVID-19 mortality during the Omicron-predominant wave have focused primarily on the inpatient/emergency room setting, and real-world data including both inpatients and outpatients are lacking. Patients diagnosed with COVID-19 (n = 27,440,148) or influenza (n = 8,179,641) from January 2020 to April 2023 were identified using nationwide claims data in Japan. Patients with COVID-19 in the Omicron-predominant wave were compared with their counterparts in earlier waves, and a subset of the former group (May 2022-April 2023) was compared with patients with influenza as controls. The mortality rates (average number of deaths/cases per week) of COVID-19 decreased over time, being 2. 7% (169/6312), 2. 1% (397/18,754), 0. 7% (195/28,273), and 0. 4% (1613/378,848) in the wild-type-, Alpha-, Delta-, and Omicron-predominant waves, respectively. However, the number of deaths increased substantially in the Omicron-predominant wave, especially among the elderly (e. g., in the Delta- and Omicron-predominant waves, the average numbers of deaths/cases per week were
| Concepts | Keywords |
|---|---|
| Influenza | COVID-19 |
| Inpatients | Influenza |
| Japan | Mortality |
| NDB |
Semantics
| Type | Source | Name |
|---|---|---|
| disease | MESH | COVID-19 |
| disease | MESH | influenza |
| disease | MESH | emergency |
| disease | MESH | Long Covid |