Transferability of Health Economic Evidence: A Quantitative Country Comparison of Acute Respiratory Infection and Influenza-like-Illness Incidence

OBJECTIVES: The health economic value of the use of rapid diagnostic tests targeting to reduce antibiotic prescriptions in patients visiting the General Practitioner (GP) with cough or sore throat was recently studied in the PRUDENCE trial. As country-specific characteristics may influence the outcome of health economic analyses, the current study examines the transferability of a health economic model across countries within the European Economic Area (EEA) by focusing on incidence of acute respiratory infections (ARIs) and Influenza-like-Illness (ILI).

METHODS: Age-specific weekly incidence of ARI and ILI from EEA countries (n=27) in the period 2010 - 2023 were derived from the European Surveillance System (TESSy) of the European Centre for Disease Control. Weekly incidence of ARI and ILI was calculated per 100,000 population and grouped by country, season (splitting at week 35), and age group (ages 0-4, 5-14, 15-64, 65 and older). Average incidence was compared between countries that participated in the PRUDENCE trial and non-participating countries.

RESULTS: Incidence of ARI and ILI was available for eight and ten countries, respectively, and varied widely across countries. Overall, average ARI incidence throughout seasons 2016-2017 to 2018-2019 was higher in trial countries (Germany, Belgium) compared to non-trial countries (Bulgaria, Czechia, Netherlands, Romania, Slovenia, Slovakia) for age groups 0-4, 15-64 and 65+ (3449 versus 2953 [+16.8%]; 1025 versus 517 [+98.4%]; 699 versus 360 per 100,000 [+93.9%], respectively), though lower for age group 5-14 (1339 versus 1546 per 100,000 [-13.4%]). Average ILI incidence was higher for all age groups in trial countries (Belgium, Ireland, Poland, Portugal) compared to non-trial countries (Czechia, Estonia, Netherlands, Romania, Slovenia, Slovakia) (178 versus 85 per 100,000 [+115%]).

CONCLUSIONS: Substantial differences in incidence of ARI and ILI were found between trial and non-trial countries and among all countries, which may influence the transferability of the health economic analysis.