Sunday, March 27, 2011

More evidence that acupuncture does not really work.

  There have been several new developments in the evidence base for the effectiveness of acupuncture recently. The first, and more important is a recent systematic review of the evidence for the effectiveness of acupuncture for pain. The Skept Vet has addressed this review in detail here. In short, the review found that the evidence for pain relief in general was contradictory and weak, with the possibility of rare but serious side effects to consider as well. As The Skept Vet points out this type of mild, patient expectation-related effect (placebo effect) may not exist in our animal patients, and any perceived effect may be due more to owner and clinician expectation and observation bias than to any real effect felt by the patient.

     Another human study was published recently on the effects of acupuncture on nausea in humans being treated for cancer. This study is interesting because it is one of the few studies which included not only a standard care control group, but also had a sham acupuncture group in addition to the acupuncture group. The sham group involved both a telescopic sham needle and a sham acupuncture point to help control for both patient perception and any effect possibly related to the specific acupuncture point used. The sample sizes in this study were not huge, but were better than many other acupuncture studies, with 62 (standard treatment), 88 (acupuncture) and 95 (sham acupuncture) patients completing the study. The participants in the study were also interviewed top measure their expectations related to the treatment.

    The results of the study showed that both the acupuncture and sham acupuncture groups  had lower levels of nausea and vomiting than the standard care group, and that this effect was strongly correlated to patient expectations. While the therapists applying the acupuncture were not blinded, the results between the two groups were not significantly different. This study is better controlled than most acupuncture studies in the past have been despite the lack of double blinding.  This reinforces the view that many skeptics have that the apparent effects of acupuncture on subjective symptoms such as the perception of pain and nausea may be due to patient expectation rather than any specific physiological effect of the acupuncture itself. Veterinarians claiming that acupuncture is effective should be very careful-their patients may be experiencing some discomfort or pain related to the acupuncture, without any benefit of expectation of improvement, while the veterinarian and owner may believe they see improvement because of their own expectations and desire to help. While an argument may be made that inducing positive expectations in human patients may be useful for managing problems such as pain and nausea, this should be done without misleading the patient or exposing them to risks of serious side effects. In the case of animal patients, it is probably unrealistic to assume that they have the same type of expectation of benefit, and we should be doubly careful to be sure the treatments we use have good evidence of effectiveness.

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