Reported effects in randomized controlled trials were compared with those of nonrandomized trials in cholecystectomy.
Müeller
Dirk
D
Institute for Research in Operative Medicine, University Witten/Herdecke, Cologne, Germany. dirkwmueller@gmx.de
Sauerland
Stefan
S
Neugebauer
Edmund A M
EA
Immenroth
Marc
M