492Complicated Intra-abdominal Infection (cIAI) and 30-day Hospital Readmission

Background. Patients with cIAI may be at increased risk of poor health outcomes post-hospital discharge. Our objective was to quantify the association between cIAI and 30-day hospital readmission. Methods. This was a retrospective cohort study of adult patients (age >18 years) with cIAI admitted to Oregon Health and Science University (OHSU) between January 1, 2010–June 30, 2013. Included patients must have had a diagnosis code consistent with cIAI, a procedure code for surgical intervention, and been discharged alive. We excluded patients with non-cIAI infectious diagnoses codes during the index admission, chronic liver disease, or those receiving peritoneal dialysis. We defined 30-day hospital readmission as readmission to OHSU within 30 days of discharge. Potential risk factors of readmission included demographics (e.g., age, sex, body mass index), comorbid illnesses (e.g., peptic ulcer disease, diabetes, cancer) and length of stay. Antibiotic exposures of interest included receipt of anaerobic coverage≥72 hours, vancomycin for≥72 hours, andmonotherapy vs combination therapy. We calculated the incidence of 30-day readmission among patients with cIAI and used bivariable analysis to identify potential predictors of 30-day readmission among these patients. We used multivariable logistic regression to identify independent risk factors for readmission within 30 days. Results. Among 259 patients with cIAI who were discharged alive, 171 patients (66%) met our inclusion criteria. Incidence of 30-day readmission was 45.6% and median (interquartile range) time to readmission was 10 (4-17) days. Total hospital length of stay > 14 days during the index admission was significantly associated with 30-day hospital readmission; odds ratio: 2.35, 95% confidence interval: 1.11 to 4.96. No other variables were identified as risk factors or had protective effects. Conclusion. Patients with cIAI were frequently readmitted to the hospital within 30 days of discharge and often following extended hospital stays. Given the lack of significant predictors to identify patients at increased risk of readmission, improvements in care for extended admissions should be considered, along with an additional emphasis on prevention of cIAI to reduce these poor outcomes. Disclosures. J. P. Furuno, Cubist Pharmaceuticals: Grant Investigator, Research grant and Research support B. N. Noble, Cubist Pharmaceuticals: Grant Investigator, Research support M. R. Elman, Cubist Pharmaceuticals: Grant Investigator, Research support J. C. Mcgregor, Cubist Pharmaceuticals: Grant Investigator, Research grant and Research support.