Using a Placebo or Sham Procedure as a Control: Ethics and Practicalities

Abstract

New surgical treatments are often introduced without proof of efficacy from randomized controlled trials, and some procedures that are perceived to be effective have never been rigorously tested. There is evidence that there is a significant placebo effect from surgical procedures and the effectiveness of some accepted procedures is due largely to this placebo effect. There is further evidence that the placebo effect from invasive procedures may be even stronger than the recognized effects of a placebo pill. An increasing number of randomized controlled trials evaluating surgical interventions have used sham, or placebo, surgeries in their control groups to account for the placebo effect. The use of placebo procedures raises important ethical and practical issues. The primary ethical concerns stem from the recognition that sham procedures necessarily cause more than minimal risk and harm, which challenges research and clinical ethics. The practical challenge of incorporating sham procedures as experimental controls involves identifying a suitable placebo procedure that can adequately maintain blinding while satisfying the ethical demands to minimize harm as much as possible.