RT Journal
A1 Lurati Buse, Giovanna A.L.
A1 Botto, Fernando
A1 Devereaux, P.J.
T1 Revisiting Sample Size: Are Big Trials the Answer?
JF The Journal of Bone & Joint Surgery
JO The Journal of Bone & Joint Surgery
YR 2012
FD July 18
VO 94
IS Suppl 1(E)
SP 75
OP 79
DO 10.2106/JBJS.K.01270
UL http://dx.doi.org/10.2106/JBJS.K.01270
AB Abstract: 
  The superiority of the evidence generated in randomized controlled trials over observational data is not only conditional to randomization. Randomized controlled trials require proper design and implementation to provide a reliable effect estimate. Adequate random sequence generation, allocation implementation, analyses based on the intention-to-treat principle, and sufficient power are crucial to the quality of a randomized controlled trial. Power, or the probability of the trial to detect a difference when a real difference between treatments exists, strongly depends on sample size. The quality of orthopaedic randomized controlled trials is frequently threatened by a limited sample size. This paper reviews basic concepts and pitfalls in sample-size estimation and focuses on the importance of large trials in the generation of valid evidence.