Applicability of press needles to a double-blind trial: a randomized, double-blind, placebo-controlled trial

Owing to a lack of a suitable needle procedure, it has been impossible to evaluate the efficacy of acupuncture in clinical studies using double-blind testing. We evaluated the applicability of a new kind of press needle (Pyonex) to a double-blind trial by comparing the press needle with a placebo (lacking the needle element).

The purpose of the study consisted of 2 phases. In the phase 1, to evaluate the applicability and efficacy of the press needles, 90 participants who had never been treated using acupuncture were randomly assigned to receive either the press needle (n=45) or a placebo (n=45). The applicability was measured using a questionnaire regarding the perception of penetration, and efficacy was measured using a visual analog scale of low back pain (LBP). When the applicability and efficacy of the press needles were confirmed in phase 1, the mechanism of LBP relief by the press needles was examined in phase 2.

In phase 1, intergroup comparisons showed no significant differences concerning the perception of penetration. In addition, for patients with LBP, the press needles reduced the subjective evaluation of LBP compared with the placebo (P<0.05). In phase 2, visual analog scale results indicated that LBP was reduced significantly more in the press needle group than in the local anesthesia group (P<0.05).

The participants could not distinguish between the press needle and a placebo, and the data from the press needle group suggested a specific influence on patients with LBP. These findings imply that the press needle and a placebo provide an effective means of realizing a double-blind setting for clinical studies of acupuncture.