Among secondary outcomes , one month after treatment those who received epidural steroid injection had greater reductions in worst leg pain ( -3.0 , SD 2.8 ) than those treated with gabapentin ( -2.0 , SD 2.9 ; P = 0.04 ) and were more likely to experience a positive successful outcome ( 66 % v 46 % ; number needed to treat = 5.0 , 95 % confidence interval 2.8 to 27.0 ; P = 0.02 ) .