Bacteremia Identified After Emergency Department Discharge in Adults: A Retrospective Analysis of Outcomes and Risk Factors.

BACKGROUND: Adults who undergo blood-culture sampling in the emergency department (ED) may be discharged before results are finalized and later found bacteremic. Factors identifying which patients require readmission are not well defined. We sought predictors of return and hospitalization available at the index ED visit. METHODS: In this retrospective study at a 1000-bed university-affiliated hospital (September 2021-March 2026), we included adults discharged from the ED with a positive blood culture identified post-discharge. The primary outcome was ED return with hospitalization within 30 days. Multivariable logistic regression was restricted to variables available at the index ED visit. RESULTS: Of 197 eligible patients, 16 were excluded, leaving 181 analyzed: 78 (43.1%) were managed as outpatients, 36 (19.9%) returned and were re-discharged, and 67 (37.0%) returned and were hospitalized. Median age was 73 (IQR 61-83) years and 105 (58.0%) were male. Index-visit vital signs and laboratory values did not differ across trajectories. The only independent predictor of return and hospitalization was a non-UTI working discharge diagnosis (aOR 2.53, 95% CI 1.3-5.0). Creatinine ≥ 2 mg/dL (aOR 2.65, 95% CI 0.9-7.5) and previous hospitalization within 6 months (aOR 1.82, 95% CI 0.8-4.1) were significant per univariate analysis but attenuated after adjustment, and age was not predictive. Enterobacterales predominated (n = 111, 61.3%). All nine endovascular-infection cases were hospitalized. Overall mortality was 1.1% (2/181). CONCLUSIONS: Post-discharge bacteremia carried low mortality but frequent ED return and hospitalization. A non-UTI working diagnosis independently identified a higher-risk minority; renal impairment and recent hospitalization were supportive but non-independent markers.