Mean differences on the PI-NRS were 1.83 cm ( 95 % CI = 14.3-20 .3 ) , 1.03 cm ( 95 % CI = 6.6-12 .7 ) , 3.13 cm ( 95 % CI = 27.2-33 .3 ) , and 2.22 cm ( 95 % CI = 18.9-25 .0 ) for the AL , SL , AE , and SE groups , respectively .