Statistical Analysis of Ginkgo-Warfarin Interaction
The comparison of bleeding events between the warfarin only and the warfarin plus Ginkgo groups was made using
Cox regression. The cumulative bleeding risk is displayed graphically with Kaplan-Meier plots. Multivariable Cox
regression models were also fitted, controlling in a fixed covariate fashion for several binary comorbidities: age 75
or older, history (Hx) of heart failure, Hx of high blood pressure, Hx of vascular diease, Hx of stroke, Hx of
diabetes, Hx of hypertension, Hx of renal disease, Hx of liver disease, and Hx of alcohol use. These comorbidities
were identified using ICD codes.