The objective of this study was to test the hypothesis that there is seasonal variation in the incidence of Stanford type A aortic dissection (SA-AoD) among patients admitted to our cardiovascular surgical service. A sinusoidal logistic regression model was used to analyze event data for 6081 calendar days. A cyclic peak risk for SA-AoD was observed for calendar day 304 (p=0.019). The odds ratios for the 3- and 6-month window surrounding this peak were 1.6 (p=0.054) and 1.7 (p=0.0040), respectively. Our results suggest than a seasonal variation exists in the incidence of SA-AoD.
Keywords: Aortic dissection; seasonality; sinusoidal logistic regression.