Impact of antibiotic changes on hospital stay and treatment duration in community-acquired pneumonia

The misuse and overtreatment of antibiotics in hospitalized patients with community-acquired pneumonia (CAP) can cause multi-drug resistance and worsen clinical outcomes. We aimed to analyze the trends and appropriateness of antibiotic changes in hospitalized patients with CAP and their impact on clinical outcomes. This retrospective study enrolled patients with CAP, aged > 18 years, admitted from January 2017 to December 2021 at Seoul National University Bundang Hospital, South Korea. We examined the pathogens identified, antibiotics prescribed, and the appropriateness of antibiotic changes as reviewed by infectious disease specialists. Antibiotic appropriateness was assessed based on adherence to the 2019 ATS/IDSA guidelines and the 2018 Korean national guidelines for CAP, targeting appropriate pathogens, proper route, dosage, and duration of therapy. Outcomes measured included time to clinical stability (TCS), length of hospital stay, duration of antibiotic treatment, and in-hospital mortality. The study included 436 patients with a mean age of 72.11 years, of whom 35.1% were male. The average duration of antibiotic treatment was 13.5 days. More than 55% of patients experienced at least one antibiotic change, and 21.7% had consecutive changes. Throughout their hospital stay, 273 patients (62.6%) received appropriate antibiotic treatment, while 163 patients (37.4%) received at least one inappropriate antibiotic prescription. Those who received at least one inappropriate prescription experienced longer antibiotic treatment durations and extended hospital stays, despite having similar TCS. In conclusion, inappropriate antibiotic prescribing in hospitalized patients with CAP is associated with prolonged antibiotic treatment and increased length of stay. Emphasizing the appropriate initial antibiotic selection may help mitigate these negative effects.