[Effects of high thermal stress on health-a nationwide analysis based on statutory health insurance routine data between 2012 and 2021].

Background: The extent to which statutory health insurance (SHI) data can be used to map associations between thermal stress and heat-related diseases is still unclear. The aim of this study is to analyse the association between climate variability and heat-associated diseases using insurance data.

Methods: The study is based on claims data (outpatient and stationary) from health insurance companies in Germany for the years 2012-2021, covering approximately 11 million people with statutory health insurance. Four heat-related ICD-10 diagnoses were considered: T67 (heat and sun damage), E86 (volume depletion), N17 (acute renal failure) and N19 (renal insufficiency). Thermal conditions were quantified using meteorological variables. The evaluation was carried out on a federal state-specific basis for the second and third quarters (Q2, Q3) using descriptive methods and correlation analyses with repeated measurements.

Results: The years 2016, 2018 and 2020 were characterised by high temperatures. Compared with Q2, Q3 was associated with higher thermal stress and more heat-related diagnoses on average during the entire observational period. Nationally, diagnoses of heat and sun damage (outpatient) correlated with the number of hot days (r_mw = 0.86 [0.81; 0.90]). Although heat stress is lower in the second quarter, a similar correlation is found here (r_mw = 0.76 [0.68; 0.82]). This striking association was also maintained when analysing the federal states specifically.

Discussion: The article shows that associations between thermal stress and morbidity can also be found in routine SHI data. Against the background of an increase in high thermal stress due to climate change, this article highlights the need for adaptation measures.