Predictors of in-hospital death among patients with COVID-19 aged < 65 who required invasive mechanical ventilation in Japan.

Background: This study investigated the characteristics, prognosis, and predictors of in-hospital death of hospitalized patients with coronavirus disease 2019 (COVID-19) aged <65 years who required invasive mechanical ventilation (IMV).

Methods: Data were obtained from the nationwide inpatient registry for COVID-19 in Japan. The data of individuals aged <65 years who received IMV between March 2020 and June 2021 were analyzed. Predictors of in-hospital death were examined using logistic regression analyses, adjusted for age and sex.

Results: Among 22,946 participants aged <65 years registered during the study period, 728 patients received IMV (median, 55 years [range; 22-64, interquartile range: 49.5-60]; males, 84.8 %); 10 % (n = 73) died in the hospital and 46.6 % (n = 305/655) of those discharged alive required oxygen therapy at discharge. After adjusting for age and sex, predictors of in-hospital death included congestive heart failure (adjusted odds ratio: 3.59, 95 % confidence interval: 1.23-10.5), chronic respiratory disease excluding chronic obstructive pulmonary disease (7.98, 2.84-22.4), diabetes with complications (3.52, 1.68-7.40), moderate-to-severe renal dysfunction (3.18, 1.36-7.46), Charlson comorbidity index ≥3 (5.16, 2.34-11.4), and complications during hospitalization such as acute respiratory distress syndrome (2.00, 1.12-3.57).

Conclusions: A substantial proportion of COVID-19 patients aged <65 with invasive mechanical ventilation died at the hospital or required oxygen at discharge, suggesting the importance of attention to younger patients, especially those with multiple comorbidities.