Real-world study on disease burden and current clinical practice of hospital-acquired pneumonia in Japan

Background: Hospital-acquired pneumonia (HAP) is a common nosocomial infection and is associated with high mortality. Despite advances in the understanding of the causes and prevention of HAP, it continues to be a frequent complication associated with hospital care. Presently, there are no large retrospective cohort studies on HAP in Japan.

Methods: A retrospective cohort study was conducted using the Medical Data Vision Co. Ltd. database for the study period (1 April 2015 to 31 May 2018). The study population was defined based on ICD-10 codes for bacterial pneumonia, characteristics of hospitalization, and prescription of injection-only antibiotics. The study included patients ≥ 18 years of age with at least one episode of HAP during the identification period, where the episode was defined as hospitalization with HAP within the study identification period.

Results: A total of 2,968 patients were included in this study contributing to 2,979 HAP episodes. Patients with HAP were more likely to be male (64.9%) and older than age 65 (86.5%). The top three frequently prescribed antibiotics were sulbactam-ampicillin (39.7%; 1,183 episodes), tazobactam-piperacillin (28.4%; 846 episodes) and ceftriaxone (23.2%; 690 episodes). The mean (± SD) length of hospital stay during overall hospitalization and the HAP period were 49.9 (± 34.2) days and 11.3 ± 7.3 days respectively. The HAP patient mortality at discharge was 22.0%.

Conclusion: The present study provided insights regarding the characteristics, treatment patterns of HAP patients in Japan. Further, the study provided noteworthy information regarding antibiotic usage trends in the aging Japanese population.