RT Journal
A1 Livingston EH
T1 BAriatric surgery centers of excellence do not improve outcomes
JF Archives of Surgery
JO Archives of Surgery
YR 2010
FD June 1
VO 145
IS 6
SP 605
OP 606
DO 10.1001/archsurg.2010.83
UL http://dx.doi.org/10.1001/archsurg.2010.83
AB 
Recently, I published an article on effect size estimation in the Archives that provided the rationale for examining the magnitude of differences between comparator groups in addition to traditional statistical significance testing.1 A tutorial was provided to facilitate determination of effect sizes for Archives readers who might not be familiar with these calculations. Statistical significance tests providing evidence that groups differ give no information regarding the magnitude or importance of the difference. Use of P values is often misleading, resulting in some leaders in the field of statistical sciences to recommend eliminating them from use all together.2