A decrease in GFR > 25 % was less likely with DE 110 mg ( hazard ratio : 0.81 [ 95 % confidence interval : 0.69 to 0.96 ] ; p = 0.017 ) or DE 150 mg ( hazard ratio : 0.79 [ 95 % confidence interval : 0.68 to 0.93 ] ; p = 0.0056 ) than with warfarin in the observation period > 18 months .