Advanced issues in the design and conduct of randomized clinical trials: the bigger the better?

Large trials provide more precise estimates of treatment effects than small trial (how good is the treatment?) and they may allow a few sensible and pre-defined sub-group analyses (for whom does the treatment work best?). But large trials will not get done unless they are simple and as part of normal clinical practice as possible. Copyright 2002 John Wiley & Sons, Ltd.