Although both groups had similar technical abilities preintervention -LSB- DP : median score , @ ( @-@ @ ) ; control : median score , @ ( @-@ @ ) ; P = @ -RSB- , the DP residents had a superior technical performance postintervention -LSB- DP : median score , @ ( @-@ @ ) ; control : median score , @ ( @-@ @ ) ; P = @ -RSB- .