Short Versus Longer Antibiotic Duration for Community-Acquired Pneumonia

BACKGROUND: Shorter antibiotic courses for community-acquired pneumonia (CAP) may reduce adverse effects and resistance. However, real-world data supporting very short durations remain limited. OBJECTIVE: To evaluate the safety and effectiveness of 3- to 4-day versus 5-day or more antibiotic durations in hospitalized patients with CAP who achieve clinical stability by day 3 (afebrile, no new oxygen, and stable vital signs). DESIGN: Observational emulation of a target trial. SETTING: 67 Michigan hospitals between 2017 and 2024. PATIENTS: Adults hospitalized (non-intensive care unit) with CAP who received 3 days of antibiotics, were clinically stable by antibiotic day 3, and met the strict eligibility criteria of the Pneumonia Short Treatment trial. INTERVENTION: 0 to 1 additional days of antibiotic treatment versus 2 or more days of additional antibiotic treatment (that is, shorter [3 to 4 days] vs. longer [≥5 days] total antibiotic duration). MEASUREMENTS: infection. RESULTS: infection (CI, 0.18 to 5.68). LIMITATION: Few short-duration patients and potential residual confounding. CONCLUSION: Only 10.1% of inpatients with CAP met the strict eligibility criteria for short-course therapy. The short- and longer-course antibiotic treatment groups had similar mortality rates, and there was little difference in benefits and harms. PRIMARY FUNDING SOURCE: Blue Cross Blue Shield of Michigan and Blue Care Network.