Editor's Choice – Temporal fluctuations of hospital incidence and mortality of ruptured abdominal aortic aneurysms in Germany: A secondary data analysis of German hospital episode statistics 2009 – 2018

Abstract

Rupture of abdominal aortic aneurysms (rAAA) is still associated with high mortality. Recent studies have shown higher incidences in autumn and winter, and worse outcomes after rAAA treatment on weekends in some countries. This study aimed to analyse for seasonal, weekday, and daytime fluctuations of the hospital incidence, treatment modalities, and outcomes of rAAA, based on most recent nationwide German real world data. A secondary data analysis of diagnosis related group statistics (2009 - 2018), obtained from the German Federal Statistical Office, was conducted. Cases encoded by a diagnosis of rAAA in conjunction with procedural codes for endovascular aortic repair (EVAR) or open aortic repair were included. Patient and procedural characteristics, comorbidities, and outcomes were analysed for seasonal (spring, summer, autumn, and winter), weekday (Monday - Sunday) and daytime (0:00 - 8:00, 8:00 -16:00, 16:00 -20:00, and 20:00 - 24:00) fluctuations by descriptive statistics and multivariable regression analyses. Thirteen thousand and seventy patients (85% male, median age 75 years) were treated for rAAA. Endovascular aortic repair was associated with lower mortality (adjusted OR 0.40, 95% CI 0.37 - 0.44). While no significant seasonal fluctuations were found, on a weekday basis lower hospital incidences were found on Mondays (12%) and Sundays (11%) compared with other weekdays (15 - 16%). Similarly, EVAR rates were lower on Mondays and Sundays (25% and 24%, respectively) compared with other weekdays (30 - 33%). Furthermore, multivariable analyses revealed higher mortalities on Mondays and Sundays. On a daytime basis, lower EVAR rates and higher mortalities were found during the 16:00 - 8:00 period. In German hospitals, incidences and EVAR rates to treat rAAA were lowest on Mondays and Sundays. The associated overall mortalities were highest on the respective days. Further structuration and centralisation of AAA treatment in Germany could potentially mitigate this weekday effect.