Clinical Characteristics Associated with Mortality between Surviving and Non-surviving Adult Patients with Severe Influenza Requiring Hospitalization: An Internet-based, Prospective, Multicenter, Cohort Study in Japan
Abstract
Introduction Influenza remains a huge issue, but its prognosis and clinical characteristics are still unclear. This study aimed to clarify the clinical differences between adults hospitalized with influenza between survivors and nonsurvivors.Methods Clinical data of patients who were severely ill with influenza and required hospitalization were gathered and analyzed between September 2019 and August 2025 (six influenza seasons) using an internet surveillance system; patients who did not survive were excluded.Results Of the 490 patients with severe influenza, 32 (6.53%) did not survive and were older than the surviving patients. In the non-surviving patients, very few or none had been vaccinated against influenza or pneumococcal infections. The non-surviving patients had more pure viral pneumonia and more received mechanical ventilation. The male-to-female ratio, underlying diseases, virus type, and use of antibiotics were similar between survivors and non-survivors.Conclusions Non-surviving patients were older and developed more severe respiratory failure due to pure viral pneumonia than surviving patients. Very low vaccination rates for influenza and pneumococcus might be suggested in hospitalized adults with severe influenza.
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BibTeX
@article{seki2026clinical,
title = {{Clinical Characteristics Associated with Mortality between Surviving and Non-surviving Adult Patients with Severe Influenza Requiring Hospitalization: An Internet-based, Prospective, Multicenter, Cohort Study in Japan}},
author = {Masafumi Seki and Akihiro Ito and Yuki Shiko and Maiko Osawa and Yukiko Oya and Kazuhiro Tateda and Jiro Fujita and Kosaku Komiya and Akihiko Kawana and Koichi Izumikawa and Toshiaki Kikuchi and Norio Ohmagari and Mitsuhiro Yamada and Takaya Maruyama and Takahiro Takazono and Makoto Miki and Yoshitsugu Miyazaki and Yoshitaka Yamazaki and Hiroshi Kakeya and Yuta Hayashi and Hideaki Nagai and Tadashi Ishida},
journal = {Internal Medicine},
year = {2026},
month = oct,
doi = {10.2169/internalmedicine.8035-26},
url = {https://www.jstage.jst.go.jp/article/internalmedicine/advpub/0/advpub_8035-26/_article},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Clinical Characteristics Associated with Mortality between Surviving and Non-surviving Adult Patients with Severe Influenza Requiring Hospitalization: An Internet-based, Prospective, Multicenter, Cohort Study in Japan
AU - Masafumi Seki
AU - Akihiro Ito
AU - Yuki Shiko
AU - Maiko Osawa
AU - Yukiko Oya
AU - Kazuhiro Tateda
AU - Jiro Fujita
AU - Kosaku Komiya
AU - Akihiko Kawana
AU - Koichi Izumikawa
AU - Toshiaki Kikuchi
AU - Norio Ohmagari
AU - Mitsuhiro Yamada
AU - Takaya Maruyama
AU - Takahiro Takazono
AU - Makoto Miki
AU - Yoshitsugu Miyazaki
AU - Yoshitaka Yamazaki
AU - Hiroshi Kakeya
AU - Yuta Hayashi
AU - Hideaki Nagai
AU - Tadashi Ishida
PY - 2026
DA - 2026/10/15
JO - Internal Medicine
DO - 10.2169/internalmedicine.8035-26
UR - https://www.jstage.jst.go.jp/article/internalmedicine/advpub/0/advpub_8035-26/_article
AB - Introduction Influenza remains a huge issue, but its prognosis and clinical characteristics are still unclear. This study aimed to clarify the clinical differences between adults hospitalized with influenza between survivors and nonsurvivors.Methods Clinical data of patients who were severely ill with influenza and required hospitalization were gathered and analyzed between September 2019 and August 2025 (six influenza seasons) using an internet surveillance system; patients who did not survive were excluded.Results Of the 490 patients with severe influenza, 32 (6.53%) did not survive and were older than the surviving patients. In the non-surviving patients, very few or none had been vaccinated against influenza or pneumococcal infections. The non-surviving patients had more pure viral pneumonia and more received mechanical ventilation. The male-to-female ratio, underlying diseases, virus type, and use of antibiotics were similar between survivors and non-survivors.Conclusions Non-surviving patients were older and developed more severe respiratory failure due to pure viral pneumonia than surviving patients. Very low vaccination rates for influenza and pneumococcus might be suggested in hospitalized adults with severe influenza.
SN - 1349-7235
SN - 0918-2918
ER -