In this issue, Michalsen et al report the results of a fascinating randomized clinical trial (RCT) of “wet cupping” for symptom control in carpal tunnel syndrome.
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Cupping, a traditional treatment that has been used in several cultures, involves creating a vacuum over certain points on the skin which, in turn, generates a small visible hematoma. Wet cupping also uses laceration of the skin so that blood is extracted from the dermal microcirculation. Cupping is claimed to work via a range of mechanisms from counter-irritation to “detoxification,” but these are mere theories that have not been tested or investigated. The results of the RCT appear to be encouraging and the authors conclude that “cupping therapy effectively relieves symptoms and pain…”1
I applaud the authors for conducting this RCT and this Journal for publishing it. All too often, we seem to either accept traditional treatments because “they have stood the test of time” or reject them untested as “old wives tales.” Neither of these attitudes is advancing our knowledge.Michalsen et al recruited their patients through a press release and randomized them into 2 groups. The experimental group received “gentle scarification by means of a microlancet,” followed by wet cupping and subsequent bandaging of the wound. The control group received no scarification, cupping, or bandaging but only a heat pack. I remember falling off my bike as a boy. The impressive bandage my mother put on my painful knee worked miracles for my pain! What I am trying to say is simple: We are conditioned to respond to nonspecific treatments, particularly if we are highly expectant, as patients recruited via a press release most likely are. This conditioning highlights the difficulties one can encounter when studying therapies such as cupping.
I am aware of 5 previous RCTs of cupping that suggest positive effects on pain.
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But they are all subject to bias and misinterpretation. Ideally we need a trial where patients are adequately blinded such that any nonspecific effects are neutralized. Michalsen et al write that “a sham cupping treatment is not available at present.” True, but it would be possible to create a good sham intervention, pilot it, and implement it in a truly rigorous RCT of cupping.My message is straightforward: it is important to conduct and publish clinical trials of traditional treatments such as cupping. When designing such studies, we often encounter methodological problems such as adequate patient blinding. If we want to be sure whether the observed effects are specific or nonspecific by nature, it is well worth being innovative to solve these problems. The ultimate aim of clinical research must be helping our patients. This, I suggest, can be achieved most reliably by determining which treatments generate more than just nonspecific effects.
References
- Effects of traditional cupping therapy in patients with carpal tunnel syndrome. A randomized controlled trial.J Pain. 2009; 10: 601-608
- Cupping for treating pain: A systematic review.Evid Based Complement Alternat Med. 2009; (May 7; Epublication ahead of print)
Article info
Publication history
Published online: April 20, 2009
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© 2009 American Pain Society. Published by Elsevier Inc. All rights reserved.
