BMJ 2001;323:1306 ( 1 December )

Letters

Acupuncture for treatment of chronic neck pain

    Reanalysis of data suggests that effect is not a placebo effect
    Authors' reply

Reanalysis of data suggests that effect is not a placebo effect

The first 150 words of the full text of this article appear below.

EDITOR---Irnich et al reported that acupuncture was superior to massage though not to sham acupuncture for neck pain.1 This suggests that acupuncture is effective but that this is due to a placebo effect.

The statistical method used (comparing improvements in pain between groups with pairwise t tests) is of questionable efficiency. Firstly, regression analysis including baseline score as a covariate has greater statistical power than comparison of change. 2 3 Secondly, each pairwise comparison in a three group trial ignores one third of the patients; such comparisons are thus underpowered when compared with regression modelling of all data.

Analysis of change scores, such as that reported, favours the group with worse baseline pain scores (in this case, the group that had sham acupuncture) because of regression to the mean4; conversely, analysis of follow up scores alone favours the group with less baseline pain. Regression analysis gives similar results regardless . . . [Full text of this article]
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Relevant Article

Randomised trial of acupuncture compared with conventional massage and "sham" laser acupuncture for treatment of chronic neck pain • Commentary: Controls for acupuncture---can we finally see the light?
Dominik Irnich, Nicolas Behrens, Holger Molzen, Achim König, Jochen Gleditsch, Martin Krauss, Malte Natalis, Edward Senn, Antje Beyer, Peter Schöps, and Mike Cummings
BMJ 2001 322: 1574. [Abstract] [Full Text] [PDF]

This article has been cited by other articles:

  • Wang, S.-M., Kain, Z. N., White, P. F. (2008). Acupuncture Analgesia: II. Clinical Considerations. Anesth. Analg. 106: 611-621 [Abstract] [Full text]  
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