The mean ( SD ) PWT at 3 months increased in the GM-CSF group from 296 ( 151 ) seconds to 405 ( 248 ) seconds ( mean change , 109 seconds [ 95 % CI , 67 to 151 ] ) and in the placebo group from 308 ( 161 ) seconds to 376 ( 182 ) seconds ( change of 56 seconds [ 95 % CI , 14 to 98 ] ) , but this difference was not significant ( mean difference in change in PWT , 53 seconds [ 95 % CI , -6 to 112 ] , P = .08 ) .