Int J Infect Dis

. 2021 Jan 9;S1201-9712(21)00019-9.
doi: 10.1016/j.ijid.2021.01.011. Online ahead of print.
Effectiveness of Oseltamivir in reducing 30-day readmissions and mortality among patients with severe seasonal influenza in Australian hospitalised patients

Yogesh Sharma 1 , Chris Horwood 2 , Paul Hakendorf 2 , Campbell Thompson 3



Background: Worldwide, seasonal influenza causes significant mortality and poses a significant economic burden. Oseltamivir is an effective treatment but benefits beyond immediate hospitalisation are unknown.
Methods: This retrospective multicentre study included adult hospitalised influenza patients from two major teaching hospitals in Australia. Patients who received Oseltamivir <48 hours of admission (prompt-treatment group) were compared with those who either did not receive treatment or if treatment was delayed by >48 hours (delayed/no-treatment group). Propensity-score matching was used to balance confounders between two groups. Primary outcomes included 30-day readmissions, 30-day mortality, composite-outcome (30-day mortality and readmissions), in-hospital mortality and hospital length of stay (LOS).
Results: Between January 2016-March 2020, 1828 adult patients mean (SD) age 66.4 (20.1), 52.9% females, were hospitalised with influenza. Four hundred and forty eight (24.5%) received prompt-treatment with Oseltamivir, while 1380 (75.5%) patients were in delayed/no-treatment group. The median (IQR) time from onset of symptoms to the administration of Oseltamivir was 3 (1-5) days. The propensity-score model, included 245 matched patients in each group (standardised mean difference of <10%). Both 30-day readmissions and the composite-outcome were, respectively, 5.7% (P = 0.03) and 6.5% (P = 0.02) lower in patients who received prompt-treatment with Oseltamivir when compared to delayed/no-treatment group. LOS showed significant reduction and in-hospital mortality showed a trend towards improvement among patients who received prompt-treatment when compared to the other group.
Conclusions: Early administration of Oseltamivir is associated with a reduction in 30-days readmissions and composite-outcome of 30-day readmissions and mortality in adult hospitalised influenza patients when compared to delayed/no-treatment.

Keywords: Influenza; Mortality; Oseltamivir; Readmissions.