Decreased hospital-acquired respiratory infections among older inpatients during the COVID-19 pandemic: a retrospective observational study in a general hospital in China.

Background: To mitigate hospital-acquired transmission of coronavirus disease 2019 (COVID-19), various prevention and control measures have been strictly implemented in medical institutions. These stringent measures can potentially reduce the incidence of hospital-acquired respiratory infections. This study aimed to assess if there were changes in the prevalence of hospital-acquired respiratory infections during a period of national attention focused on COVID-19 prevention.

Methods: A retrospective analysis of the clinical data from adult patients with hospital-acquired respiratory infections admitted between October and December 2019 and during the same period in 2020 was performed. All patients were referred from a general hospital in Beijing China and COVID-19 patients were not treated at the hospital. Hospital-acquired respiratory infections were diagnosed based on the criteria of the Centers for Disease Control and Prevention/National Healthcare Safety Network (CDC/NHSN). A comparison of the incidence and mortality rate of hospital-acquired respiratory infections between the two selected time periods was conducted. Additionally, multivariate logistics regression analysis was used to identify mortality-associated risk factors.

Results: This study included 2,211 patients from October to December 2019 (pre-COVID-19 pandemic) and 2,921 patients from October to December 2020 (during the COVID-19 pandemic). The incidence of hospital-acquired respiratory infections in 2019 and 2020 was 4.7% and 2.9%, respectively, with odds ratio (OR): 0.61, 95% confidence interval (CI): 0.46-0.81, and P = 0.001. In-hospital mortality of hospital-acquired respiratory infections in 2019 and 2020 was 30.5% and 38.4%, respectively, with OR: 1.42, 95%CI: 0.78-2.59, and P = 0.25. Multivariate logistics regression analysis revealed that a history of previous malignancy (OR: 2.50, 95%CI: 1.16-5.35, P = 0.02), was associated with in-hospital mortality.

Conclusions: The incidence of hospital-acquired respiratory infections was significantly decreased following the implementation of various prevention and control measures during the COVID-19 pandemic. A history of previous malignancy was associated with higher in-hospital mortality in older inpatients with hospital-acquired respiratory infections.