Costs associated with influenza-related hospitalization in the elderly.

Abstract

Seasonal influenza epidemics remain a considerable burden in adults, especially in those at higher risk of complications. The aim of this study was to determine the costs associated with influenza-related hospitalization in patients aged ≥65 y admitted to 20 hospitals from 7 Spanish regions during the 2013-14 and 2014-15 influenza seasons. Bivariate analysis was used to compare costs in vaccinated and unvaccinated cases. Costs were calculated according to the Spanish National Health System diagnosis-related group tables for influenza and other respiratory system conditions (GRD 89 and GRD 101). A total of 728 confirmed influenza cases were recorded: 52.9% were male, 46.7% were aged 75-84 years, and 49.3% received influenza vaccine ≥15 d prior to hospital admission. Influenza-related mean hospitalization costs (MHC) were € 1,184,808 in unvaccinated and € 1,152,333 in vaccinated cases (2.75% lower). Influenza vaccination showed significant protection against ICU admission (OR 0.35, 95%CI 0.21-0.59; p