Short Versus Longer Antibiotic Duration for Community-Acquired Pneumonia : A Multicenter Target Trial Emulation.

Area of Science:

• Infectious Diseases
• Clinical Medicine
• Pharmacology

Background:

• Shorter antibiotic courses for community-acquired pneumonia (CAP) could decrease adverse effects and resistance.
• Real-world data on very short antibiotic durations for CAP are limited.

Purpose of the Study:

• To assess the safety and effectiveness of 3- to 4-day antibiotic durations compared to 5-day or longer durations.
• To evaluate outcomes in hospitalized CAP patients who achieved clinical stability by day 3.

Main Methods:

• Observational study emulating a target trial in 67 Michigan hospitals (2017-2024).
• Included non-ICU hospitalized adults with CAP meeting strict eligibility criteria for short-course therapy.
• Compared 3- to 4-day total antibiotic duration (short-course) versus ≥5 days (long-course).

Main Results:

• Of 55,517 CAP patients, only 10.1% met eligibility for short-course therapy.
• Short-course (3-4 days) vs. long-course (≥5 days) showed similar 30-day mortality (aRR 0.89), readmission (aRR 1.07), urgent visits (aRR 0.94), and C. difficile infection (aRR 1.01).
• Median antibiotic duration was 7 days; only 7.9% received 3-4 days.

Conclusions:

• A small proportion of hospitalized CAP patients met strict criteria for very short antibiotic courses.
• Short-course antibiotic therapy demonstrated comparable safety and effectiveness to longer courses for eligible patients.
• Findings suggest potential for reduced antibiotic exposure in select CAP patients, though residual confounding is possible.