Mean drug cost difference between B0 ( 430.6 euros , SEM 406.0 ) and B1 ( 221.2 euros , SEM 58.7 ) ( P = 0.870 ) became significant after excluding outlier drug costs ( B0 , 184.4 euros , SEM 42.5 ; B1 , 90.5 euros , SEM 17.7 ; P < 0.001 ) .