RT Journal
A1 Whelan, Daniel B.
A1 Dainty, Katie
A1 Chahal, Jaskarndip
T1 Efficient Designs: Factorial Randomized Trials
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 34
OP 38
DO 10.2106/JBJS.L.00243
UL http://dx.doi.org/10.2106/JBJS.L.00243
AB Abstract: 
  As an alternative to conducting multiple parallel group randomized controlled trials, the factorial design is an efficient means of evaluating multiple interventions. This review highlights when it is appropriate to conduct a factorial trial, considers the structure and nomenclature of factorial designs, and discusses various methodological considerations, including sample size calculation, the role of statistical interactions between different interventions, and statistical power. Several pertinent examples in orthopaedics and medicine are used to highlight the key concepts.