Advances in Double-Blind Research

One of the biggest gold standards for efficacy in scientific research is the double-blind study. When both patients and practitioners are blinded to treatment method, there can be no bias from expectation or attitude. While there have been a number of well-designed, single-blind acupuncture studies in which the patient was unaware of the treatment methodology, there have been no previous studies of an acupuncture procedure or a placebo needle that also can successfully blind the practitioner as to efficacy.

Now, a study published in the Oct. 10 issue of Complementary and Alternative Medicine may have found a solution to this dilemma. Two researchers from Japan have developed a placebo acupuncture needle with a blunt tip that is designed to mimic the feel of an actual penetrating needle, both to patient and practitioner. The needle is designed with a special opaque guide tube, so that neither practitioner nor patient can tell whether the tip is blunt or sharp.

In order to try out the needle, the researchers conducted two tests - one with practitioners and one with patients. In the first study, 10 practitioners each applied 23 non-penetrating needles and 17 penetrating ones into the Large Intestine-4 point, without knowing beforehand which type of needle they were using. After removing each needle, practitioners were asked whether the needle was penetrating, non-penetrating or unidentifiable.

The practitioners failed to identify 16 percent of the needles and identified them incorrectly 42 percent of the time. This was regardless of years of experience in the field.

In the second half of the study, 60 healthy volunteers who were familiar with receiving acupuncture were recruited. Two randomized pairs of 60 needles were used. Patients were asked if they felt a skin-penetration sensation from each needle or de qi, a deep dull pain sensation that is considered essential for a successful acupuncture treatment. Additionally, practitioners were asked to guess the authenticity of the needle after removal. For this portion of the study, "unidentifiable" was removed as an option.

None of the subjects stated that they had been treated with a non-penetrating needle. Of the 60 penetrating and 60 non-penetrating needle applications, 80 percent and 42 percent elicited skin-penetration sensations and 80 percent and 33 percent elicited a feeling of de qi, respectively. Furthermore, the practitioners identified 54 percent of the needles correctly and 45 percent incorrectly.

The researchers concluded, "For double-blind acupuncture studies, real and placebo needles must be identical for all variables except skin penetration. This is the ultimate aim underlying the design of the needles; they must fit these preconditions. The appearance and feel of the non-penetrating placebo and penetrating needles in this study were virtually identical, such that even well-experienced acupuncturists required deliberation to determine whether a needle was real or placebo. The findings that 16 percent of all needles were unidentifiable and that the practitioners identified approximately 50 percent of the other needles incorrectly indicate the potential of these needles in practitioner masking."

Although it will still need to be determined if this type of needle is suitable for other points on the body, such as toes or scalp, this may well provide much more valuable data to support the efficacy of acupuncture as a treatment modality.