The impact of weather factors, moon phases, and seasons on abdominal aortic aneurysm rupture.

BACKGROUND

Several studies have documented that weather factors, seasons of the year, time of the day, and even changes in moon phases have an impact on the occurrence of rupture of an abdominal aortic aneurysm (RAAA); however, the available data are confounding. The objective of this study was to determine the impact of these factors on the prevalence and mortality rate of RAAA.

METHODS

This is a retrospective analysis of medical records of patients treated for RAAA over a 10-year period. Weather data (i.e., atmospheric pressure, air temperature, humidity, visibility, and wind speed) and weather events (i.e., rain, snow, and storms, etc) were obtained from the local meteorologic weather station and analyzed for a correlation with RAAA.

RESULTS

Five hundred thirty patients with RAAA were identified, and these patients presented on 478 days during the 10-year study period (3,652 days), with the overall in-hospital mortality rate of 48.7%. The RAAA mortality was higher during weekends and national holidays, when compared to weekdays (59% vs 45%; P = 0.006) and in patients admitted between 3-7 am when compared to work day hours (65.5% vs 44.1%; P = 0.035). Season changes had no influence on the frequency of RAAA; however, summer seemed to be associated with an increase in mortality as opposed to autumn (54.4% vs 42.5%; P = 0.047). Mean atmospheric pressure (and fluctuations thereof) and other weather factors, including phases and parts of the moon, did not correlate with RAAA occurrence or its mortality.

CONCLUSIONS

Patients with RAAA who were admitted on weekends, national holidays and in late night hours had lower survival rates. Weather factors (including atmospheric pressure) do not influence the prevalence and mortality of RAAA.