Influenza affects patients, health systems and economies

The burden from influenza is manifold:

• There are numerous disease cases that may be fatal or cause hospitalisation.
• There are even larger numbers of mild to moderate cases that result in a multiplication of working days called off sick causing loss of productivity in the working population.

These effects are often of great economic impact. The burden of influenza varies from year to year, however, which makes it hard to estimate the annual number of deaths. The costs caused by an illness are mainly calculated by computing the sum of all direct, indirect and intangible costs.

Direct costs are influenced by chronic underlying conditions and other risk factors (e.g. age), which may lead to increases in hospital admissions and prolonged treatments. Influenza constitutes a substantial socioeconomic burden for society in terms of medical treatments, increases in consultations, hospitalisations, clinical complications and drug use as well as increased work absenteeism (Commission of the European Communities, 2009).

Visits to clinics, physicians’ offices, or hospital emergency rooms may increase greatly during epidemics and pandemics. Lower-respiratory tract and cardiac complications can lead to substantial increases in hospital admissions and deaths, and healthcare resources can be severely strained during influenza epidemics (Cox & Subbarao, 1999).

There are different estimates of the total economic impact of an influenza epidemic. For example, the total impact of an influenza epidemic in industrialised countries may reach 56.7 million € per million people. In several different studies a total costs of 987.8 million € was estimated for Germany in1996-1997 influenza epidemic; the total cost of influenza was estimated at more than 1,796 million € in France; and in the United States, the yearly total costs have been calculated at approximately 10,000–17,000 million € (Commission of the European Communities, 2009).