Table 4.

Study reporting the outcome of ASA or warfarin intake alone in a subgroup cohort

			Boorjian et. al.10 2009
G1/G2			170/737	52/855
Anticoagulant			ASA	Warfarin
Univariate analyses using Kaplan-Meier /log-rank test	- Recurrence in G1		- N/A	- N/A
	- Time to recurrence (range)		- Median: 7 months*	- Median: 7 months*
	- 5-year risk of recurrence		- N/A	- N/A
	- Progression		- N/A	- N/A
	- Time to progression		- N/A	- Median: 2.1 years
	- 5-year risk of progression		- 34%**	- 65%**
	- Recurrence in G2		- N/A	- N/A
	- Time to recurrence (range)		- Median: 6 months*	- Median: 6 months*
	- 5-year risk of recurrence		- N/A	- N/A
	- Progression		- N/A	- N/A
	- Time to progression		- N/A	- Median: 9 years
	- 5-year risk of progression		- 44%**	- 41%**
	p value		*p = 0.6 (NS)	*p = 0.14 (NS)
			**p = 0.029	**p = <0.01
	Results summary:		- Similar recurrence in both groups	- Similar recurrence in both groups
			- Sig. more prog. in Gp2.	- Significantly more progression in G1
Multivariate analyses	Recurrence	Impact of 1 anticoagulant medication in a cohort of patients taking any 1 or more anticoagulant	- NS difference among both groups	- NS difference among both groups
			- HR: 0.91 (0.75- 1.10)	- HR: 1.19 (0.89-1.59)
			- p = 0.3	- p = 0.2
		Impact of 1 anticoagulant medication in a cohort of patients only taking 1 anticoagulant	- NS difference among both groups (data not shown)	- Significantly increased risks in G1
				- HR: 1.39, 95% CI (1-1.94)
				- p = 0.047
	- Progression		- Significantly decreased risk of progression to open surgery	- Significantly increased risks in G1
				- HR: 1.89, 95% CI (1.31-2.74)
			- HR: 0.71, 95%CI (0.52-0.96)	- p = 0.0007
			- p = 0.024
	- Statistical tests		- Cox proportional hazards regression model
	- Controlled covariates		- Age, initial tumour stage (superficial vs. invasive) and anticoagulation medication used

Asterisks indicate data used for p value calculations. N/A: not available; NS: non-significant; G: group; HR: hazard ratio; CI: confidence interval.