Inpatient Burden of Influenza and Influenza-Like Illness Among Adults Aged 60 and Older in Germany 2019-2024
Author(s)
Anna Meyer, PhD1, Saskia Kiesel, MSc2, Moritz Wick, MSc2, Oliver Damm, DrPH2.
1EbM / HEOR Managerin, Sanofi-Aventis Deutschland GmbH, Berlin, Germany, 2Sanofi-Aventis Deutschland GmbH, Berlin, Germany.
1EbM / HEOR Managerin, Sanofi-Aventis Deutschland GmbH, Berlin, Germany, 2Sanofi-Aventis Deutschland GmbH, Berlin, Germany.
OBJECTIVES: Data on the influenza burden in Germany during and after the global SARS-CoV-2 pandemic are scarce. This study presents nationwide trends in the clinical and economic inpatient burden of influenza and influenza-like illness (ILI) in the older German population from 2019-2020 to 2023-2024.
METHODS: All inpatient episodes with an ICD-10 diagnosis of J09-J11 as the primary cause of hospitalization among individuals aged 60+ were extracted from a nationwide hospital database (InEK). An influenza season was defined as a 12-month period from July to June of the following year. The number of influenza/ILI hospitalizations was reported for each season together with the mean length of stay, patient characteristics, and proportions treated in intensive care units (ICU). Crude and age-standardized hospitalization incidence per 100,000 inhabitants was calculated for each season for Germany and for each German federal state. Inpatient costs were estimated based on recorded diagnosis-related group (DRG) codes.
RESULTS: We observed 13,964, 502, 1192, 23,058, and 28,789 influenza/ILI hospitalizations among individuals aged 60+ in 2019-2020, 2020-2021, 2021-2022, 2022-2023, and 2023-2024, respectively. Mean length of stay each season ranged from 7.8 to 10.7 days and between 4% and 13% of cases were treated in ICU. Mean hospitalization costs per season ranged from €2977 to €6901. Hospitalization incidence varied considerably between seasons and federal states with higher crude and age-adjusted incidence in southern Germany. In 2023-2024, crude incidence rates per 100.000 inhabitants aged 60 and older ranged from 55.8 in Brandenburg to 172.4 in Bavaria.
CONCLUSIONS: Despite a temporary decline in influenza/ILI activity following the SARS-CoV2 pandemic, recent seasons were associated with an increasing burden of influenza/ILI in the older German population. Incidence was especially high in southern Germany where public health authorities observed particularly poor influenza vaccination coverage rates. Public health efforts to promote influenza vaccination and reduce the burden of influenza remain important.
METHODS: All inpatient episodes with an ICD-10 diagnosis of J09-J11 as the primary cause of hospitalization among individuals aged 60+ were extracted from a nationwide hospital database (InEK). An influenza season was defined as a 12-month period from July to June of the following year. The number of influenza/ILI hospitalizations was reported for each season together with the mean length of stay, patient characteristics, and proportions treated in intensive care units (ICU). Crude and age-standardized hospitalization incidence per 100,000 inhabitants was calculated for each season for Germany and for each German federal state. Inpatient costs were estimated based on recorded diagnosis-related group (DRG) codes.
RESULTS: We observed 13,964, 502, 1192, 23,058, and 28,789 influenza/ILI hospitalizations among individuals aged 60+ in 2019-2020, 2020-2021, 2021-2022, 2022-2023, and 2023-2024, respectively. Mean length of stay each season ranged from 7.8 to 10.7 days and between 4% and 13% of cases were treated in ICU. Mean hospitalization costs per season ranged from €2977 to €6901. Hospitalization incidence varied considerably between seasons and federal states with higher crude and age-adjusted incidence in southern Germany. In 2023-2024, crude incidence rates per 100.000 inhabitants aged 60 and older ranged from 55.8 in Brandenburg to 172.4 in Bavaria.
CONCLUSIONS: Despite a temporary decline in influenza/ILI activity following the SARS-CoV2 pandemic, recent seasons were associated with an increasing burden of influenza/ILI in the older German population. Incidence was especially high in southern Germany where public health authorities observed particularly poor influenza vaccination coverage rates. Public health efforts to promote influenza vaccination and reduce the burden of influenza remain important.
Conference/Value in Health Info
2025-11, ISPOR Europe 2025, Glasgow, Scotland
Value in Health, Volume 28, Issue S2
Code
EE555
Topic
Economic Evaluation, Epidemiology & Public Health
Topic Subcategory
Cost/Cost of Illness/Resource Use Studies
Disease
Infectious Disease (non-vaccine), No Additional Disease & Conditions/Specialized Treatment Areas