729. Comparing Length of Stay and Clinical Outcomes for Hospitalized Patients at Bridgeport Hospital who Received Baloxavir Marboxil (BM) or Oseltamivir Phosphate (OP) During the 2018–2019 Influenza Season

BACKGROUND: BM has been approved for the management of acute uncomplicated influenza in otherwise healthy individuals between age 12 and 64, and found to have a greater reduction in viremia. The original trial excluded hospitalized patients and those with co-morbidities. METHODS: This is a single-center, retrospective analysis of hospitalized patients diagnosed with influenza between October 1, 2018 and March 31, 2019. This study excluded those diagnosed before the addition of BM to the hospital formulary; those who were not treated with antivirals, treated before admission, or treated with both antivirals; those younger than 12 years old; and those who remain hospitalized. The relationship between length of stay and antiviral used was ascertained using t-test and multivariate linear regression. Due to heterogeneity in reasons for hospitalization, analysis was stratified by the main reasons for hospitalization. T-test and Wilcoxon’s rank-sum test were used for continuous variables, and Pearson’s chi-squared test was used for categorical variables. The significance level was 0.05. RESULTS: The study population (n = 145) has a mean age of 66.5 years; of whom, 43% are male. In terms of patient characteristics, those treated with BM (n = 105) vs. OP (n = 40) were older, less frequently admitted to ICU and of differing ethnic composition. The length of stay was similar in those treated with BM vs. OP in both univariate and multivariate linear regression (5.5 (5.3) vs. 8.2 (11.4) days, P = 0.33). In addition, the length of stay was similar in those treated with BM vs. OP when stratified by reasons for hospitalization: pneumonia/bronchitis (6.6 (7.1) vs. 8.2 (9.2) days, P = 0.43), obstructive airway disease exacerbation (5.5 (4.8) vs. 4.8 (8.0) days, P = 0.56), elderly with multiple co-morbidities (5.0 (4.0) vs. 3.4 (6.8) days, P = 0.63), reactive airway disease (4.1 (4.8) vs. 7.4 (1.5) days, P = 0.27) or congestive heart failure exacerbation (9.8 (9.0) vs. 5.6 (5.0) days, P = 0.43). CONCLUSION: In hospitalized patients with co-morbidities diagnosed with influenza, there was no difference in length of stay in those who received BM vs. OP. This highlights the need to clarify the role of BM in this population, particularly given its comparable symptom reduction, greater cost, and the emergence of PA138T viral mutant. DISCLOSURES: All authors: No reported disclosures.