What is the placebo worth?
The doctor-patient relationship is a crucial part of its value, say David Spiegel and Anne Harrington
George Bernard Shaw described a miracle as “an event that creates faith.” Belief is a powerful tool, and many factors influence it. A recent study testing pain relief from analgesics showed that merely telling people that a novel form of codeine they were taking (actually a placebo) was worth $2.50 (£1.25; €1.58) rather than 10 cents increased the proportion of people who reported pain relief from 61% to 85.4%.1 When the “price” of the placebo was reduced, so was the pain relief. A meta-analysis of decades of clinical trials proposed that the placebo effect was more hype than reality.2 However, the resulting backlash against it has had the implicit effect of clarifying what is best practice with regard to the placebo.3
Hovering over much of the research is a practical question for clinicians—what does all this mean for patient care? In the accompanying randomised controlled trial, Kaptchuk and colleagues undertake