Introduction:
Population-based data on incidence and mortality risk factors, particularly in very elderly patients with traumatic subarachnoid hemorrhage (tSAH) are limited. This study analyzed epidemiology, comorbidities, complications, age-specific incidence rates, and predictors of in-hospital mortality in patients with tSAH in Germany, with a focus on those aged ≥80 years.

Material and methods:
This retrospective cross-sectional study included all hospitalized patients with tSAH (ICD-10 S06.6) in Germany from 2019 to 2022, using nationwide administrative data from the Institute for the Hospital Remuneration System (InEK-GmbH). Demographics, comorbidities, complications, diagnostic procedures, ICU treatment, and in-hospital mortality were analyzed. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using univariable analyses. Age-specific incidence rates were derived from Federal Statistical Office (Destatis) population data.

Results:
In a nationwide cohort of 67,684 tSAH patients, in-hospital mortality was 9.1%. The incidence of tSAH was 34.4 per 100,000 and increased sharply with age. Hypertension (44.5%) and atrial fibrillation (14.8%) were common. Mortality was higher in patients with atrial fibrillation (OR 1.86), cardiac pacemakers (OR 1.65), and three-vessel coronary artery disease (OR 1.54). Prolonged unconsciousness (>24 h) was the strongest predictor of death (OR 16.32), followed by cerebral edema (OR 4.70). Septic shock, renal failure, and traumatic shock carried the highest mortality risk.

Discussion and conclusion:
tSAH is associated with substantial in-hospital mortality, particularly in very elderly patients and those with cardiac comorbidities. These predictors/associations may support risk stratification and early intensive care management.