Estimating the burden of influenza-related and associated
hospitalizations and deaths in France: an eight-season data study,
2010-2018
Abstract
Background: In France, each year, influenza viruses are responsible for
seasonal epidemics leading to 2-6 million cases. Influenza can cause
severe disease that may lead to hospitalization or death. As severe
disease may be due to the virus itself or to disease complications,
estimating the burden of severe influenza is complex. The present study
aimed at estimating the epidemiological and economic burden of severe
influenza in France during eight consecutive influenza seasons
(2010-2018). Methods: Influenza-related hospitalization and mortality
data and patient characteristics were taken from the French hospital
information database, PMSI. An ecological approach using cyclic
regression models integrating the incidence of influenza syndrome from
the Sentinelles Network supplemented the PMSI data analysis in
estimating excess hospitalization and mortality (CépiDc – 2010-2015)
and medical costs. Results: Each season, the average number of
influenza-related hospitalizations was 18,979 (range: 8,627-44,024),
with an average length of stay of 8 days. The average number of
respiratory hospitalizations indirectly related with influenza (i.e.,
influenza-associated) was 31,490 (95% CI: 24,542-39,012), with an
average cost of \euro141 million (range: 54-217); 70% of these
hospitalizations and 77% of their costs concerned individuals ≥ 65
years of age (65+). More than 90% of excess mortality was in 65+
subjects. Conclusions: The combination of two complementary approaches
allowed estimation of both influenza-related and associated
hospitalizations and deaths and their burden in France, showing the
substantial impact of complications. The present study highlighted the
major public health burden of influenza and its severe complications,
especially in 65+ subjects.