Incidence of Tick-Borne Encephalitis in Germany Comparison of Claims Data With Public Surveillance Data
Author(s)
Guy Levy, M.Sc.1, Isabel Karkossa, Dr. rer. nat.2, Julia Schiffner-Rohe, Dr.1, Christof von Eiff, Prof. Dr. med.1, Gerhard Dobler, Prof. Dr. med.3, Claudius Malerczyk, Dr.1.
1Pfizer Pharma GmbH, Berlin, Germany, 2Gesundheitsforen Leipzig GmbH, Leipzig, Germany, 3Institut für Mikrobiologie der Bundeswehr, Munich, Germany.
1Pfizer Pharma GmbH, Berlin, Germany, 2Gesundheitsforen Leipzig GmbH, Leipzig, Germany, 3Institut für Mikrobiologie der Bundeswehr, Munich, Germany.
OBJECTIVES: Since the introduction of mandatory reporting of tick-borne encephalitis (TBE) in Germany in 2001, the Robert Koch Institute (RKI) has annually reported between 195 and 705 cases that meet the official case definition, which includes laboratory test confirmation. This study investigates the incidence of TBE in Germany using statutory health insurance (SHI) claims data and compares it with RKI reported figures.
METHODS: We conducted a retrospective cohort analysis using the German Analysis Database for Evaluation and Healthcare Research (DADB), which comprises representative data of up to 3 million SHI patients annually between 2013-2022. Incident TBE cases were identified via ICD-10 code A84, recorded as either confirmed outpatient diagnoses or primary/secondary inpatient diagnoses, with no TBE diagnoses in the preceding year. Diagnostic testing, TBE vaccination, concurring diagnoses, care settings, hospitalization and mortality were also examined. Analyses were stratified by region, age and sex.
RESULTS: Between 2014 and 2022, we identified 2,572 incident TBE cases in the DADB. In 84%, vaccination was coded simultaneously with TBE diagnosis. Excluding those resulted in 411 cases, 20% of which were initially diagnosed in the inpatient setting and a further 10% of the outpatients were later hospitalized. Extrapolated to the SHI population, this translates to approximately 12,041 cases (95% CI: 10,659-13,317), which is approximately three times the 4,054 cases reported by the RKI during the same period. Notably, only 48% of these cases had documentation of indicative laboratory testing.
CONCLUSIONS: Claims data revealed significantly higher TBE incidence than reported by RKI. The low test rates identified may partially account for this discrepancy. Additionally, widespread simultaneous coding of TBE vaccination and TBE diagnosis suggests common miscoding or, possibly, post-exposure vaccination. Even after excluding those cases, incidence rate remains high, indicating potential surveillance gaps, e.g. underdiagnosis and underreporting. Further investigation is needed to better understand clinical, diagnostic and documentation practices.
METHODS: We conducted a retrospective cohort analysis using the German Analysis Database for Evaluation and Healthcare Research (DADB), which comprises representative data of up to 3 million SHI patients annually between 2013-2022. Incident TBE cases were identified via ICD-10 code A84, recorded as either confirmed outpatient diagnoses or primary/secondary inpatient diagnoses, with no TBE diagnoses in the preceding year. Diagnostic testing, TBE vaccination, concurring diagnoses, care settings, hospitalization and mortality were also examined. Analyses were stratified by region, age and sex.
RESULTS: Between 2014 and 2022, we identified 2,572 incident TBE cases in the DADB. In 84%, vaccination was coded simultaneously with TBE diagnosis. Excluding those resulted in 411 cases, 20% of which were initially diagnosed in the inpatient setting and a further 10% of the outpatients were later hospitalized. Extrapolated to the SHI population, this translates to approximately 12,041 cases (95% CI: 10,659-13,317), which is approximately three times the 4,054 cases reported by the RKI during the same period. Notably, only 48% of these cases had documentation of indicative laboratory testing.
CONCLUSIONS: Claims data revealed significantly higher TBE incidence than reported by RKI. The low test rates identified may partially account for this discrepancy. Additionally, widespread simultaneous coding of TBE vaccination and TBE diagnosis suggests common miscoding or, possibly, post-exposure vaccination. Even after excluding those cases, incidence rate remains high, indicating potential surveillance gaps, e.g. underdiagnosis and underreporting. Further investigation is needed to better understand clinical, diagnostic and documentation practices.
Conference/Value in Health Info
2025-11, ISPOR Europe 2025, Glasgow, Scotland
Value in Health, Volume 28, Issue S2
Code
EPH144
Topic
Epidemiology & Public Health, Health Policy & Regulatory
Topic Subcategory
Disease Classification & Coding
Disease
Infectious Disease (non-vaccine), Vaccines