The intervention group 's primary outcome scores improved relative to the control group , however when clustering was taken into account , the findings were non-significant : self-rated EBP behavior [ effect size 4.97 ( 95 % CI -10.47 , 20.41 ) ( p = 0.52 ) ] ; peer-rated EBP behavior [ effect size 5.86 ( 95 % CI -17.77 , 29.50 ) ( p = 0.62 ) ] .