RT Journal
A1 Rogers SJ, Cello JP
T1 ERcp or laparoscopic exploration for the treatment of suspected choledocholithiasis?—reply
JF Archives of Surgery
JO Archives of Surgery
YR 2010
FD August 1
VO 145
IS 8
SP 796
OP 796
DO 10.1001/archsurg.2010.129
UL http://dx.doi.org/10.1001/archsurg.2010.129
AB 
We read the comments of Singh et al with interest. As we mentioned in our response to the letter from Drs Yashimski and Poulose, we did perform an a priori power sample size calculation in the approved protocol design of the study. Although we had proposed 4 individual primary end points for the study, we chose length of stay as the end point upon which to calculate sample size. Our calculations estimated that we would need a sample of 100 patients per group. We decided to close the study, however, following 6 years of randomization. There is indeed a possibility of a type II error as mentioned in our response to the letter of Drs Yashimski and Poulose.