Burden of seasonal influenza in the Swiss adult population during the 2016/2017-2018/2019 influenza seasons

BackgroundEvidence on the burden of seasonal influenza in Switzerland is scarce, yet it is critical for the design of effective prevention and control measures. The objective of this study was to assess influenza-related resource utilization, health care expenditures and quality-adjusted life-years (QALYs) lost in Switzerland across the 2016/2017-2018/2019 influenza seasons.MethodsWe retrospectively analyzed multiple real-world data sources to calculate epidemiological and health outcomes, QALYs lost, and direct medical costs due to influenza in the Swiss adult population. Subgroups included residents 18-49, 50-64, and 65+ years of age. The observation period was Week 26, 2016, to Week 25, 2019.ResultsAcross the three seasons, we estimated seasonal averages of 203,090 (se +/- 26,717) general practitioner (GP) visits for influenza-like illness (ILI) 4944 (se +/- 785) influenza-attributable hospitalizations and 1355 (se +/- 169) excess deaths attributable to influenza. We estimated a total loss of 8429 (2016/2017), 11,179 (2017/2018), and 7701 (2018/2019) QALYs due to influenza. On average, 88% of the loss in QALYs was attributed to premature deaths due to influenza.The total direct medical costs amounted to 44.4 (2016/2017), 77.3 (2017/2018), and 64.5 (2018/2019) million euros. On average, 79.6% of the total costs arose due to hospitalizations.ResultsAcross the three seasons, we estimated seasonal averages of 203,090 (se +/- 26,717) general practitioner (GP) visits for influenza-like illness (ILI) 4944 (se +/- 785) influenza-attributable hospitalizations and 1355 (se +/- 169) excess deaths attributable to influenza. We estimated a total loss of 8429 (2016/2017), 11,179 (2017/2018), and 7701 (2018/2019) QALYs due to influenza. On average, 88% of the loss in QALYs was attributed to premature deaths due to influenza.The total direct medical costs amounted to 44.4 (2016/2017), 77.3 (2017/2018), and 64.5 (2018/2019) million euros. On average, 79.6% of the total costs arose due to hospitalizations.ConclusionsIn Switzerland, the burden of influenza on patients and payers is significant and particularly high in the elderly population. Policy interventions to increase vaccination rates and the uptake of more effective vaccines among the elderly are needed to reduce the burden of influenza.

Automated summary

The burden of influenza in Switzerland is significant, particularly among the elderly population. Policy interventions, such as increasing vaccination rates and promoting the use of more effective vaccines, are needed to reduce the burden of influenza.