Can Acupuncture Treatment Be Double-Blinded? An Evaluation of Double-Blind Acupuncture Treatment of Postoperative Pain

Abstract

Blinding protects against bias but the success of blinding is seldom assessed and reported in clinical trials including studies of acupuncture where blinding represents a major challenge. Recently, needles with the potential for double-blinding were developed, so we tested if acupuncture can be double-blinded in a randomized study of sixty-seven patients with acute pain ≥ 3 (0-10 scale following third molar removal) who received active acupuncture with a penetrating needle or placebo acupuncture with a non-penetrating needle. To test if acupuncture was administered double-blind, patients and acupuncturists were asked about perceived treatment allocation at the end of the study. To test if there were clues which led to identification of the treatment, deep dull pain associated with needle application and rotation (termed “de qi” in East Asian medicine), and patients’ pain levels were assessed. Perceived treatment allocation depended on actual group allocation (p < 0.015) for both patients and acupuncturists, indicating that the needles were not successful in double-blinding. Up to 68% of patients and 83% of acupuncturists correctly identified the treatment, but for patients the distribution was not far from 50/50. Also, there was a significant interaction between actual or perceived treatment and the experience of de qi (p = 0.027), suggesting that the experience of de qi and possible non-verbal clues contributed to correct identification of the treatment. Yet, of the patients who perceived the treatment as active or placebo, 50% and 23%, respectively, reported de qi. Patients’ acute pain levels did not influence the perceived treatment. In conclusion, acupuncture treatment was not fully double-blinded which is similar to observations in pharmacological studies. Still, the non-penetrating needle is the only needle that allows some degree of practitioner blinding. The study raises questions about alternatives to double-blind randomized clinical trials in the assessment of acupuncture treatment.

Comparison of the placebo effect between different non-penetrating acupuncture devices and real acupuncture in healthy subjects: a randomized clinical trial

“…Some placebo acupuncture devices that intended to mask both acupuncturist and patient were not effective to do it as acupuncturists found that it was a fake device, while the volunteers believed it was real acupuncture [43, 44]. Other studies have shown that placebo acupuncture technique is not effective to mask even the patient [1, 45].…”

Blinding Indices and Blinding Scenarios of Practitioners and Patients with Acupuncture Needles for Double Blinding

“…3 The patient BIs for study Ib 3 reported by Moroz et al were not appropriate. Therefore, we report practitioner-sourced BIs, which have not been presented before, along with patient BIs from five validation studies [3][4][5][6][7] (table 1). The BI (ranging from −1 to 1) is a statistical tool that can be used to objectively assess the effectiveness of blinding and has been recently introduced into acupuncture studies.…”

“…2 Table 1 shows the BIs derived from our studies [3][4][5][6][7] employing pairs of penetrating real and skin-touch placebo needles 3 4 6 7 or penetrating real needles only. 5 The overall practitioner BIs for both penetrating real and skin-touch placebo needles indicate 'random guesses', which means that the effectiveness of practitioner blinding seems promising.…”

“…5 The overall practitioner BIs for both penetrating real and skin-touch placebo needles indicate 'random guesses', which means that the effectiveness of practitioner blinding seems promising. The practitioner BI in study V, 7 in which acupuncturists adopted the Chinese style of needle administration, indicates 'unblinding' for both real and placebo needles. On the other hand, acupuncturists adopted the Japanese style of needle administration in other studies.…”

“…For patient blinding scenarios in table 1, the 'random guess' for the skin-touch placebo arm appears promising because the patient BI of skin-touch placebo needles was 0.2 in study V, 7 in which patients guessed the nature of the treatment with five needles, whilst 'random guess' was indicated by the BIs in study II 4 and study IV. 6 By contrast, the 'random guess' status for the penetrating real arm appears to be extremely difficult since the statuses in all studies were 'unblinded', as reported by a previous review.…”