Sham devices may have a greater placebo effect than inert pills

In patients with persistent arm pain, a sham acupuncture needle may enhance the placebo effect in comparison with an inert pill. In a randomised controlled trial of 270 adults, Kaptchuk and colleagues (p 391) compared the two placebo treatments and found that a 10 point arm pain scale showed greater downward slopes in the sham device group than in the placebo pill group (-0.33 v -0.15; P = 0.0001). They found no differences for arm function and grip strength.

Figure 1.

Credit: MAURO FERMARIELLO/SPL