Planta Med 2011; 77(13): 1473-1476
DOI: 10.1055/s-0030-1271044
Perspectives
© Georg Thieme Verlag KG Stuttgart · New York

Control in the Middle (CIM) for Three-Period Crossover Studies

Jonathan Shuster1 , Stephen D. Anton2 , 3 , Douglas Theriaque4 , Saunjoo Yoon5
  • 1Department of Health Outcomes and Policy, College of Medicine (COM), University of Florida, Gainesville, Florida, USA
  • 2Department of Aging and Geriatric Research (COM), University of Florida, Gainesville, Florida, USA
  • 3Department of Clinical and Health Psychology, University of Florida, Gainesville, Florida, USA
  • 4Clinical and Translational Science Institute (COM), University of Florida, Gainesville, Florida, USA
  • 5Department of Adult and Elderly, College of Nursing, University of Florida, Gainesville, Florida, USA
Further Information

Publication History

received March 3, 2011 revised March 31, 2011

accepted April 1, 2011

Publication Date:
20 April 2011 (online)

Preview

Abstract

Three-period crossover studies can be efficient and convenient methods of conducting Phase II clinical trials. Non-randomly placing control in the middle (CIM) has not been practiced but may be extremely useful in studies testing herbal products for which placebos are not available, or for distinguishing between behavioral and biological effects. Furthermore, this design can serve as a valuable addition to classical studies of either (a) two competing treatments or (b) treatment versus placebo versus an open label “nothing” as the control. Therefore, we propose rigorous designs that will help practitioners efficiently answer research questions where (1) two active treatments need to be compared against each other with treatment vs. placebo comparisons being of secondary importance; (2) a single active treatment needs to be tested where no placebo is available; or (3) the placebo effect is of interest in a treatment vs. placebo trial. For studies where no placebo is available, deception will be required, with participants told that in one randomly selected period (#1 or #3) they will receive the active treatment, and that they will receive a new experimental inert placebo in the other period. Assuming this design is approved by an ethics committee, it can be very useful in biomedical research.

References

Jonathan J. Shuster

Department of Health Outcomes and Policy, College of Medicine (COM)
University of Florida

PO Box 100177

Gainesville, FL 32610-0177

USA

Phone: +1 35 22 65 25 48

Email: jshuster@biostat.ufl.edu