Introduction: Auricular acupuncture is given as a treatment for drug dependence. Points are usually chosen on the assumption that the body is represented somatotopically in the ear, although there is no anatomical basis for this. In clinical trials, sham treatment is often given at points that are supposedly 'incorrect' for the condition, in the belief that they are inactive. The aim of this study was to explore whether there is any difference in the effectiveness of auricular acupuncture at 'correct' and 'incorrect' points.
Methods: Controlled trials of semi-permanent auricular acupuncture or acupressure for smoking cessation were systematically located, and the results combined in exploratory meta-analyses which took into account the study quality.
Results: Thirteen studies were included. Combining ten studies showed auricular acupuncture at 'correct' points to be more effective than control interventions, odds ratio 2.24 (95% CI 1.61, 3.10), a result which is confirmed in the four high validity studies. Other analyses showed inconsistent results between all studies and higher quality studies. Comparisons of three higher quality studies suggest that 'correct' and 'incorrect' point acupuncture is no different (odds ratio 1.22, CI 0.72, 2.07); and two studies showed that 'incorrect' point acupuncture may be more effective than other interventions (odds ratio 1.96, CI 1.00, 3.86).
Conclusion: Auricular acupuncture appears to be effective for smoking cessation, but the effect may not depend on point location. This calls into question the somatotopic model underlying auricular acupuncture and suggests a need to re-evaluate sham controlled studies which have used 'incorrect' points. Further experiments are necessary to confirm or refute these observational conclusions.