In the last two decades, randomized controlled trials (RCTs) have been used to evaluate the efficacy of traditional Chinese medicine (TCM) therapies. In most cases, these trials have investigated herbal drugs . However, limitations exist when conducting RCTs for non-herbal therapies such as acupuncture, cupping therapy, and moxibustion. Therapeutic effects can be influenced by factors other than the efficacy of the interventions themselves;such actors may include patient preference, practitioner preference, and patient-practitioner relationship, among others . Based on the design principle of RCTs, participants are precluded from making their own choices during allocation to the intervention or control arms to avoid performance bias due to strong preference of participants who are not blinded during the trial. Unfortunately, there is no ideal placebo control for most types of non-drug therapies, which means successful blinding is almost impossible for these types of trials.
RCTs for non-drug therapies also have limitations associated with patient recruitment and adherence due to their preference of treatment . Patients who visit TCM hospitals seeking non-drug treatment are likely to prefer such therapy. This not only increases the difficulty of recruiting for RCTs (especially for the control group) but also may lead to a high dropout rate during the trial.
A partially randomized, patient preference (PRPP) trial has been recommended for use in trials with potential performance bias [4–6]. This model was first applied for evaluating the therapeutic effect of surgery as compared with drugs, in which blinding methods could not be used due to the obvious inconformity between intervention and control treatment. Currently, this type of trial is widely used in studies that assess the effectiveness of a non-drug treatment (such as surgery) [7–11]. Given the limitations of a classical RCT, the PRPP model may be more suitable for evaluating non-drug TCM therapies. To date, there is no report on such trials in China to assess non-drug TCM therapies. Thus, our study is aimed at exploring the feasibility of applying the PRPP model to appraise the therapeutic effect of two kinds of non-drug therapies, acupuncture and cupping, while accounting for patient preference.
For this PRPP trial, we have chosen fibromyalgia as the target disease for three reasons. First, as a disorder with nonspecific symptoms of chronic widespread musculoskeletal pain and stiffness [12, 13], fibromyalgia appears to affect increasing numbers of people and has a detrimental impact on their quality of life . Second, acupuncture has been widely used for treating this condition . Third, for pain conditions, the primary outcome is usually defined as pain relief as measured by a pain intensity instrument, such as a visual analog scale, which is based on patients’ subjective reporting and may be affected by belief, expectation, or preference of treatment modality.
Many kinds of TCM non-drug modalities are used to treat fibromyalgia. Acupuncture appears to have the most benefit in improving the main symptoms of fibromyalgia compared with herbal remedies [16–20]; thus, it is often recommended as an alternative therapy for this disorder . Cupping therapy is an ancient Chinese healing modality. After systematically searching and analyzing clinical studies published in the last 50 years that used cupping therapy as the main intervention, we found that 70 of 550 studies evaluated cupping therapy for pain conditions . From these studies, it appears that cupping therapy is effective for pain reduction in general, but few studies looked at cupping therapy for fibromyalgia. Our report  on medicinal cupping for fibromyalgia found that, after cupping therapy, the visual analogue scale (VAS) scores of 30 participants were reduced by 52.3% from baseline and the number of tender points was 30.9% fewer than in baseline. In China, acupuncture and cupping therapy are commonly used in TCM hospitals for pain management, but there have been no trials comparing these two treatment modalities for fibromyalgia.
The objectives of this trial are to assess the feasibility of applying the PRPP trial model in evaluating the therapeutic effect of acupuncture versus cupping, and to observe and compare the efficacies of these two therapies for fibromyalgia.