tetano
Editor, Senior Moderator
Clin Exp Nephrol
. 2026 Jan 23.
doi: 10.1007/s10157-026-02814-z. Online ahead of print.
Mortality comparison between the COVID-19 Omicron variant and influenza among patients with end-stage kidney disease: a nationwide population-based retrospective cohort study
Tomoyuki Fujikura[SUP] 1 [/SUP], Koichi Miyashita[SUP] 2 [/SUP], Hironao Hozumi[SUP] 2 [/SUP], Yuri Ishino[SUP] 3 [/SUP], Naoko Katahashi[SUP] 4 [/SUP], Naoko Tsuji[SUP] 5 [/SUP], Sayaka Ishigaki[SUP] 5 [/SUP], Takamasa Iwakura[SUP] 3 [/SUP], Shinsuke Isobe[SUP] 5 [/SUP], Kazuki Furuhashi[SUP] 2 [/SUP], Naro Ohashi[SUP] 4 [/SUP], Toshiyuki Ojima[SUP] 6 [/SUP], Takafumi Suda[SUP] 2 [/SUP], Hideo Yasuda[SUP] 3 [/SUP]
Affiliations
Background: Although the SARS-CoV-2 Omicron variant demonstrates lower mortality than previous variants in the general population, its impact on patients with end-stage kidney disease (ESKD) remains concerning. Substantial mortality has been reported in patients with ESKD during the Omicron period; however, comparing this with influenza mortality could provide insights into COVID-19's true impact in this high-risk population.
Methods: Using the National Database of Health Insurance Claims of Japan, we conducted a retrospective cohort study of hemodialysis patients diagnosed with COVID-19 during the Omicron period (January 2022-March 2023) or influenza (September 2017-March 2023). The primary outcome was 30-day all-cause mortality. Overlap weighting based on propensity scores balanced confounding factors.
Results: We identified 53,047 COVID-19 and 35,808 influenza cases. After overlap weighting, the 30-day mortality rates were 3.4% for COVID-19 and 1.8% for influenza (hazard ratio
1.61 [95% CI 1.47, 1.77]). In subgroup analyses stratified by age, HRs were comparable across all age groups (20-49 years: 1.59 [0.81, 3.13]; 50-59 years: 1.43 [0.94, 2.17]; 60-69 years: 1.45 [1.15, 1.84]; 70-79 years: 1.68 [1.43, 1.96]; ≥ 80 years: 1.66 [1.45, 1.89]). The absolute risk differences (per 1,000 patients) across age groups were 1.7, 2.6, 6.2, 16.2, and 28.9 deaths, respectively.
Conclusions: In this nationwide study, COVID-19 Omicron variant was associated with significantly higher mortality than influenza in hemodialysis patients. Age-stratified analyses showed consistent relative risks but progressively larger absolute risk differences in older patients.
Keywords: Coronavirus disease 2019; Hemodialysis; Influenza; Mortality; Omicron.
. 2026 Jan 23.
doi: 10.1007/s10157-026-02814-z. Online ahead of print.
Mortality comparison between the COVID-19 Omicron variant and influenza among patients with end-stage kidney disease: a nationwide population-based retrospective cohort study
Tomoyuki Fujikura[SUP] 1 [/SUP], Koichi Miyashita[SUP] 2 [/SUP], Hironao Hozumi[SUP] 2 [/SUP], Yuri Ishino[SUP] 3 [/SUP], Naoko Katahashi[SUP] 4 [/SUP], Naoko Tsuji[SUP] 5 [/SUP], Sayaka Ishigaki[SUP] 5 [/SUP], Takamasa Iwakura[SUP] 3 [/SUP], Shinsuke Isobe[SUP] 5 [/SUP], Kazuki Furuhashi[SUP] 2 [/SUP], Naro Ohashi[SUP] 4 [/SUP], Toshiyuki Ojima[SUP] 6 [/SUP], Takafumi Suda[SUP] 2 [/SUP], Hideo Yasuda[SUP] 3 [/SUP]
Affiliations
- PMID: 41571947
- DOI: 10.1007/s10157-026-02814-z
Background: Although the SARS-CoV-2 Omicron variant demonstrates lower mortality than previous variants in the general population, its impact on patients with end-stage kidney disease (ESKD) remains concerning. Substantial mortality has been reported in patients with ESKD during the Omicron period; however, comparing this with influenza mortality could provide insights into COVID-19's true impact in this high-risk population.
Methods: Using the National Database of Health Insurance Claims of Japan, we conducted a retrospective cohort study of hemodialysis patients diagnosed with COVID-19 during the Omicron period (January 2022-March 2023) or influenza (September 2017-March 2023). The primary outcome was 30-day all-cause mortality. Overlap weighting based on propensity scores balanced confounding factors.
Results: We identified 53,047 COVID-19 and 35,808 influenza cases. After overlap weighting, the 30-day mortality rates were 3.4% for COVID-19 and 1.8% for influenza (hazard ratio
1.61 [95% CI 1.47, 1.77]). In subgroup analyses stratified by age, HRs were comparable across all age groups (20-49 years: 1.59 [0.81, 3.13]; 50-59 years: 1.43 [0.94, 2.17]; 60-69 years: 1.45 [1.15, 1.84]; 70-79 years: 1.68 [1.43, 1.96]; ≥ 80 years: 1.66 [1.45, 1.89]). The absolute risk differences (per 1,000 patients) across age groups were 1.7, 2.6, 6.2, 16.2, and 28.9 deaths, respectively.
Conclusions: In this nationwide study, COVID-19 Omicron variant was associated with significantly higher mortality than influenza in hemodialysis patients. Age-stratified analyses showed consistent relative risks but progressively larger absolute risk differences in older patients.
Keywords: Coronavirus disease 2019; Hemodialysis; Influenza; Mortality; Omicron.