Associations Between Antibiotic Use and Outcomes in Patients Hospitalized With Community-Acquired Pneumonia and Positive Respiratory Viral Assays

BACKGROUND: Newly released community-acquired pneumonia (CAP) guidelines include a conditional recommendation to treat all hospitalized patients with positive respiratory virus assays with antibacterials. We assessed the frequency, duration, and outcomes of antibacterial prescribing in this population. METHODS: We retrospectively identified all hospitalized patients with possible CAP and a positive respiratory virus test at 5 hospitals, June 2015-December 2024. We used detailed clinical data to propensity-weight patients treated with 0-2 versus 5-7 days of antibacterials and compared outcomes overall and for different viruses. RESULTS: Among 6779 patients with possible CAP and a respiratory virus, 3269 were treated with 0-2 days and 1560 with 5-7 days of antibacterials. After propensity-weighting 2614 patients (1720 treated 0-2 days, 894 treated 5-7 days), there were no significant differences in hospital length of stay (11.7 days vs 11.1 days; OR 1.05, 95% CI .97-1.15), ICU admission after 48 hours (28.3% vs 28.2%; OR 1.01, 95% CI .86-1.18), in-hospital mortality (9.5% vs 9.8%; OR 0.97, 95% CI .74-1.27), or 30-day hospital-free days (16.9 days vs 17.0 days; OR 0.99, 95% CI .95-1.03). Results were consistent when restricted to non-SARS-CoV-2 viruses and to influenza alone, when comparing 0 versus 5-7 days of antibacterials, and when restricting to patients with ICD-10 codes for pneumonia present on admission. CONCLUSIONS: Antibacterial use for patients with possible CAP and respiratory viruses is highly variable but outcomes are similar with 0-2 versus 5-7 days of antibacterials. This suggests antibiotics are not beneficial in most CAP patients who test positive for respiratory viruses.