Clinical Outcomes Associated with Oral Versus Intravenous Antibiotic Therapy in Emergency Department-Discharged Patients with Community-Acquired Pneumonia.

Background: Community-acquired pneumonia (CAP) remains a leading cause of emergency department (ED) visits, hospitalizations, and mortality worldwide. The choice between oral (PO) and intravenous (IV) antibiotic administration in the ED varies based on patient presentation and provider preference, yet the impact of this choice on clinical outcomes, including revisit rates and ED length of stay (LOS), remains unclear. This study aimed to compare PO versus IV antibiotic therapy in CAP patients discharged from the ED in terms of baseline characteristics, treatment outcomes, and healthcare utilization. Method: This retrospective cohort study was conducted at a tertiary care ED at the Ministry of National Guard Health Affairs in Saudi Arabia. Adult patients diagnosed treated with antibiotic for CAP and discharged from the ED between 2020-2024 were included. Patients were categorized into two groups based on antibiotic administration: POIV. The primary results were ED LOS and 30-day revisit rates. Secondary outcomes included time to first antibiotic administration, fluid administration patterns, and baseline risk factors. Data was extracted from the electronic health record and analyzed using descriptive and inferential statistics. Results: A total of 430 patients were included, with 162 (37.7%) receiving PO antibiotics and 268 (62.3%) receiving IV antibiotics. Baseline characteristics showed higher heart rate, respiratory rate, and temperature in the IV group, suggesting more severe presentations. The mean ED LOS was similar between groups (oral: 6.5 ± 4.9 h vs. IV: 6.4 ± 4.5 h; p = 0.5559). However, the 30-day ED revisit rate was significantly lower in the IV group (23.1%) compared to oral group (34.0%) (p = 0.0146). IV fluids were administered more frequently in the IV group (60.4% vs. 22.2%). Conclusions: While both PO and IV antibiotic strategies resulted in similar ED LOS, IV antibiotic use was associated with a significantly lower 30-day revisit rate. These findings support the need for risk-based treatment decisions in the ED and highlight opportunities for antibiotic stewardship to improve patient outcomes.