Table 3.

Stratified Cox regression model for intent-to-treat population. The stratification factor is the presence or absence of Tis.

Variable	Estimate	Std error	P-value	Hazard ratio (95% CI)
treatment*	−0.37	0.32	0.25	0.69 (0.37, 1.29)
Tumor Grade	−0.13	0.19	0.50	0.88 (0.61, 1.27)
Aspirin (≤100mg/day)	0.08	0.35	0.81	1.09 (0.55, 2.14)
NSAID	0.35	0.43	0.42	1.42 (0.61, 3.29)
previous smoker₣	−0.43	0.49	0.38	0.65 (0.25, 1.70)
current smoker₣	−0.46	0.38	0.23	0.63 (0.30, 1.33)

^*Placebo arm is taken as the reference group

^₣non-smoker is taken as the reference group.