We'll keep this brief...
This “evidence-based study” out of the Journal of Traditional
Chinese Medicine used surprisingly good methods looking at the efficacy of
acupuncture for a variety of cardiac problems.
But due to fatal flaws, the majority of the details and the
conclusion to this paper are irrelevant. Nevertheless it does provide some
great opportunity for learning & teaching critical appraisal of the
literature.
This systematic review found 21 articles that investigated
acupuncture for angina. Unfortunately none of them were blinded, had allocation concealment or had sham
acupuncture arms. Therefore all of the proposed benefit could easily be explained by the theatrical placebo of acupuncture. All prior good quality studies of acupuncture
using proper blinding have shown it is no better than placebo.
The paper does mention these methodology issues and go so
far as to say “all studies were assessed as
having a high or moderate risk of bias.” Had they stopped here everything
would have been fine. But they made the tragic mistake of proceeding to a
meta-analysis and making ludicrous conclusions.
There are some statistical truths. No amount of analysis can remove bias from a
study (simple confounding is a different matter). Nor can bias be overpowered
by increasing the study size.
Put another way, they completely missed the crucial backbone
of meta-analysis. If all you find is rubbish, you don’t combine it in a blender
and expect a golden egg to appear. You’ve still got rubbish.
Covering:
Chen J, Ren Y, Tang Y,
et al. Acupuncture therapy for angina pectoris: a systematic review. J Tradit
Chin Med 2012;32(4):494-501.
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