gms | German Medical Science

Objective: In recent decades, the global incidence of aneurysmal subarachnoid hemorrhage (aSAH) has declined, mainly due to the effects of more widespread medical treatment of arterial hypertension and decreasing smoking habits. However, significant regional differences exist. So far, no evidence has emerged on time trends in the prevalence of aSAH in Germany.

Methods: Data on all patients hospitalized in Germany between 2005 and 2018 with International Classification of Diseases (ICD) codes I60.0 to I60.7 were provided by the German Federal Statistical office and included in the analysis. The prevalence of the main diagnosis aSAH was analyzed on two levels 1) for the entire German population and 2) in relation to all patients hospitalized with any disease during the respective time-period. Mortality for hospitalized patients was assessed based on the number of patients who died due to respective ICD codes in relation to all patients hospitalized with the same ICD codes. Ethical approval was granted by local authorities (EA 1/275/20).

Results: The occurrence of the main diagnosis of aSAH per 100.000 inhabitants remained stable between 2005 (8.9) and 2018 (8.2). In the same period, the overall number of patients hospitalized with any disease increased from 16.1 million to 18.8 million. Therefore, the proportion of aSAH patients per 100.000 patients hospitalized with any disease decreased from 45.8 in 2005 to 36.3 in 2018. There were substantial changes in age distributions over time. Younger patients in 2005 (age group 30-45 years) comprised a higher proportion of patients affected by aSAH (21.1%) than in 2018 (11.7%). On the other hand, the proportion of older patients with aSAH increased over time (for ages 45-60: 39.3 vs. 42.1%; 60-75 years: 26.1 vs. 28.9%; above 75 years: 10.6 vs. 15.3%). In the same period, the duration of hospital stay increased from 19.7 to 24.8 days. Among patients hospitalized with aSAH, mortality rates remained stable (16.2 vs. 16.6%).

Conclusion: The overall occurrence of the main diagnosis SAH in Germany remained stable between 2005 and 2018, as did the corresponding mortality. The observed decrease in the proportion of younger individuals affected by aSAH over time might reflect smoking having become less popular among younger people. The increase in the proportion of older patients with aSAH may explain the observed increase in length of hospital stay and may also reflect the increasing life expectancy in western societies.