Population-wise incidence and outcomes of patients requiring invasive and non-invasive mechanical ventilation in China: a nationwide retrospective analysis by age, sex, and comorbidity

BACKGROUND: Mechanical ventilation is a critical yet labor-intensive medical resource with limited availability. However, population-based data on its utilization and outcomes remain scarce in China. This study aimed to describe the characteristics, frequency, and outcomes of mechanical ventilation at the national level in China. METHODS: In this multicenter cross-sectional study, we retrospectively identified hospitalized patients who received mechanical ventilation using data from the National Data Center for Medical Service. The dataset included information on patient characteristics, length of hospital stays, procedures, diagnoses, and discharge outcomes. The population selected for this study included all mechanically ventilated patients admitted between January 1, 2022 and December 31, 2022. We analyzed the distribution characteristics of patients requiring mechanical ventilation by type of ventilation. Case fatality rates were calculated and further stratified by age, sex, and comorbidity burden. RESULTS: The study included 1,641,809 admissions from 2,837 hospitals, with all patients receiving mechanical ventilation. The median age of the patients was 66.0 years (interquartile range: 51.0-76.0). Among them, 64.4% received invasive mechanical ventilation (IMV) only, while 29.0% received non-invasive ventilation (NIV) only. The incidence of mechanical ventilation was 186.5 per 100,000 population. Patients receiving IMV only had longer hospital stays and a higher comorbidity burden, compared with those receiving NIV. 41.4% of invasively ventilated patients had a diagnosis of cerebrovascular disease. In contrast, chronic pulmonary disease was the most common comorbidity (57.0%) in NIV patients. The NIV failure rate observed in our study was 7.9%. Overall, 12.8% of mechanically ventilated patients died during hospitalization, with a marked difference in case fatality rate between IMV patients (16.2%) and those receiving NIV only (5.5%). Increasing age and a higher Charlson index were both associated with a stepwise increase in mortality risk. CONCLUSIONS: Significant variations in epidemiological characteristics by age, sex, and comorbidity were observed across different modalities of mechanical ventilation. Mortality rates were markedly higher among patients receiving IMV compared to those receiving NIV, with the differences most pronounced among elderly patients, males, and those with greater comorbidity burden.