Potential savings resulting from avoided hospitalizations and avoided productivity losses due to low influenza vaccination coverage in Poland

Introduction
Annual vaccination against influenza can prevent 59% of influenza-related illness in healthy individuals. However, influenza vaccination coverage rate in Poland remains low, and at a rate of around 3% it is significantly below most other European Union countries, and in particular the United Kingdom (UK), where it is above 60%. The objective of this study is to analyze the potential savings for the Polish health care system based on the assumption that the influenza coverage rate in Poland would be the same as in the UK.

Material and methods
The total number of influenza and influenza-like infections in 2016 in Poland stood at 4.3 million. Based on the data from the Sentinel System, we classified 41% of them as confirmed influenza cases. Influenza vaccination coverage among the general population in this period was 3.4% in Poland and 61.1% in the UK. The literature gives six categories of potential costs associated with a diagnosis of influenza. Because of poor availability of health care cost data, this study captures only part of the real influenza cost in Poland. Our model evaluated two types of potential savings associated with higher influenza vaccines rate: avoided productivity loss and avoided costs of pulmonary hospitalization connected with the influenza virus.

Results
In the hypothetical scenario in which influenza coverage rate in Poland would be the same as in the UK, Poland could avoid almost 35% of current influenza incidence, which equals over 617 thousand cases in 2016. The yearly cost of pulmonary hospitalization due to influenza in Poland was PLN 7.1 million, while the cost of productivity loss due to influenza was estimated at PLN 161.6 million. These costs added to PLN 168.7 million, or PLN 94.68 per an infected individual. We estimate the savings connected with lower productivity loss and pulmonary hospitalization frequency for Polish society, if the influenza coverage rates were on the UK level, at PLN 58.4 million.

Conclusions
The results of our analysis demonstrate that an increase in influenza vaccination coverage would generate significant economic savings for the Polish health care and social security system.