title: Specifying the nonspecific components of acupuncture analgesia.
abstract: It is well known that acupuncture has pain-relieving effects, but the contribution of specific and especially nonspecific factors to acupuncture analgesia is less clear. One hundred one patients who developed pain of ≥ 3 on a visual analog scale (VAS, 0 to 10) after third molar surgery were randomized to receive active acupuncture, placebo acupuncture, or no treatment for 30 min with acupuncture needles with potential for double-blinding. Patients' perception of the treatment (active or placebo) and expected pain levels (VAS) were assessed before and halfway through the treatment. Looking at actual treatment allocation, there was no specific effect of active acupuncture (P=.240), but there was a large and significant nonspecific effect of placebo acupuncture (P<.001), which increased over time. Interestingly, however, looking at perceived treatment allocation, there was a significant effect of acupuncture (P<.001), indicating that patients who believed they received active acupuncture had significantly lower pain levels than those who believed they received placebo acupuncture. Expected pain levels accounted for significant and progressively larger amounts of the variance in pain ratings after both active and placebo acupuncture (up to 69.8%). This is the first study to show that under optimized blinding conditions, nonspecific factors such as patients' perception of and expectations toward treatment are central to the efficacy of acupuncture analgesia and that these factors may contribute to self-reinforcing effects in acupuncture treatment. To obtain an effect of acupuncture in clinical practice, it may therefore be important to incorporate and optimize these factors.
authors.affiliation: Department of Psychology and Behavioural Sciences, Aarhus University, Aarhus, Denmark Danish Pain Research Center, Aarhus University Hospital, Aarhus, Denmark Section of Clinical Oral Physiology, Department of Dentistry, Aarhus University, Aarhus, Denmark Section of Oral and Maxillofacial Surgery and Oral Pathology, Department of Dentistry, Aarhus University, Aarhus, Denmark Department of Acupuncture and Moxibustion, Tokyo Ariake University of Medical and Health Sciences, Tokyo, Japan Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA Unit for Psychooncology and Health Psychology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Lene
authors.initials: L
authors.lastname: Vase
authors.forename: Sara
authors.initials: S
authors.lastname: Baram
authors.forename: Nobuari
authors.initials: N
authors.lastname: Takakura
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Yajima
authors.forename: Miho
authors.initials: M
authors.lastname: Takayama
authors.forename: Ted J
authors.initials: TJ
authors.lastname: Kaptchuk
authors.forename: Søren
authors.initials: S
authors.lastname: Schou
authors.forename: Troels Staehelin
authors.initials: TS
authors.lastname: Jensen
authors.forename: Robert
authors.initials: R
authors.lastname: Zachariae
authors.forename: Peter
authors.initials: P
authors.lastname: Svensson
mesh_terms: D015667:Acupuncture Analgesia; D015669:Acupuncture Points; D000704:Analysis of Variance; D000779:Anesthetics, Local / Q000627:therapeutic use; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008012:Lidocaine / Q000627:therapeutic use; D008297:Male; D059408:Pain Management; D010147:Pain Measurement; D010149:Postoperative Pain / Q000628:therapy*; D015990:Placebo Effect; D012044:Regression Analysis; D012189:Retrospective Studies; D014095:Tooth, Impacted / Q000601:surgery
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine
keywords: Acupuncture analgesia; Expectation; Nonspecific; Perception; Placebo analgesia