Effectiveness of Oseltamivir in reducing 30-day readmissions and mortality among patients with severe seasonal influenza in Australian hospitalised patients.

Abstract

BACKGROUND\nWorldwide, seasonal influenza causes significant mortality and poses a significant economic burden. Oseltamivir is an effective treatment but benefits beyond immediate hospitalisation are unknown.\n\n\nMETHODS\nThis retrospective multicentre study included adult hospitalised influenza patients from two major teaching hospitals in Australia. Patients who received Oseltamivir <48\u2009hours of admission (prompt-treatment group) were compared with those who either did not receive treatment or if treatment was delayed by >48\u2009hours (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).\n\n\nRESULTS\nBetween 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\u2009=\u20090.03) and 6.5% (P\u2009=\u20090.02) 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.\n\n\nCONCLUSIONS\nEarly 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.