Short-course treatment for community-acquired pneumonia in adults aged less than 65 years in Japan: A descriptive study using large healthcare claims database

J Infect Chemother. 2025 May;31(5):102698. doi: 10.1016/j.jiac.2025.102698. Epub 2025 Apr 8.

Abstract

Introduction: In community-acquired pneumonia (CAP), short-course treatment is not inferior in effectiveness compared to conventional treatment durations, and clinical guidelines recommend 5-7-day-long treatments. However, it remains unclear how widely this practice is adopted in Japan. This study aimed to clarify the treatment duration of CAP in Japan using a large healthcare claims database.

Methods: We used health insurance claims data provided by JMDC Inc. (Tokyo, Japan) and included patients aged 18-64 years diagnosed with CAP who began antibiotic treatment between January 1, 2013, and December 31, 2022. Short-course treatment was defined as ≤ 7 d. Analyses were conducted separately for inpatient and outpatient cases, and the annual trends were also investigated.

Results: Overall, 25,572 patients (3367 inpatients and 22,205 outpatients) were included in the analysis. Short-course treatment was administered to 1087 (32 %) inpatients and 15,614 (70 %) outpatients. The proportion of short-course treatments during the 10-year study period was 31-35 % for inpatient cases and 67-72 % for outpatient cases, with no marked changes over the years.

Conclusions: The proportion of inpatients receiving short-course treatments for CAP was low. In Japan, especially for inpatient cases, further efforts are required to optimize the duration of CAP treatment.

Keywords: Administrative claims data; Community-acquired pneumonia; Treatment duration.

MeSH terms

  • Adolescent
  • Adult
  • Anti-Bacterial Agents* / administration & dosage
  • Anti-Bacterial Agents* / therapeutic use
  • Community-Acquired Infections* / drug therapy
  • Community-Acquired Infections* / epidemiology
  • Community-Acquired Pneumonia
  • Databases, Factual
  • Duration of Therapy
  • Female
  • Humans
  • Japan / epidemiology
  • Male
  • Middle Aged
  • Pneumonia* / drug therapy
  • Pneumonia* / epidemiology
  • Young Adult

Substances

  • Anti-Bacterial Agents