I have recently written about the problems with the decision by the National Institute for Health and Care Excellence (NICE) to include acupuncture in their draft guidelines on chronic pain. Here, I’m going to look at one of the studies they used as a basis for that decision in more detail. It includes a number of serious issues that means the results are unlikely to be accurate.
Study Overview
The study in question is “German Randomized Acupuncture Trial for chronic shoulder pain (GRASP) – a pragmatic, controlled, patient-blinded, multi-centre trial in an outpatient care environment”. The hypothesis for the study was “There is a significant difference for the responder rate in the verum group compared to that of sham and of COT. The patients with a pain reduction of at least 50% compared to baseline were classified as responders.” (Note that “verum” in this case refers to the acupuncture treatment group and COT is short for conservative orthopaedic treatment). Patient self-assessment of pain levels on a visual analogue scale (VAS) was used as the measurement. This primary endpoint was assessed 3 months after the completion of the 6 weeks of treatment.
The study claimed: “The trial indicates that Chinese acupuncture is an effective alternative to conventional orthopaedic treatment for CSP”. Due to the many flaws in this study, this trial doesn’t actually show this at all.
Main Flaws in the Study
Here are some of the main issues with this study:
- Use of traditional acupuncture points. The study states that the following points were used: “ventral – Lung 1, 2; ventrolateral – Large Intestine 4, 11, 14, 15; lateral – Sanjiao 5, 13, 14; dorsal – Small Intestine 3, 9”. Traditional Chinese acupuncture is based on Qi and meridians, which are ideas that conflict with modern science. These traditional acupuncture points don’t actually exist.
- Delay in publication. Patients were recruited between 1997 and 1999 but the paper was only submitted for publication in March 2009, a full ten years later. There may have been valid reasons for this but it is certainly unusual and raises concerns. Even if there were genuine reasons for such an extended delay, it seems reasonable to expect that the paper authors would struggle to remember full details of the trial after such an extended period.
- Drop-outs and how these were handled in the analysis. Drop-outs were high, particularly in the sham arm. Only 74 out of 135 (just 55%) in the sham arm reached the primary endpoint. In the treatment arm 128 out of 154 (83%) reached this point, along with 106 out of 135 (79%) in the conservative orthopaedic treatment (COT) arm. In all cases the drop-outs were “treated as non responders”. The problem with this is the very high drop-out rate in the sham arm. Treating the people who have dropped out from the sham arm as “non responders” is likely to underestimate the improvement in this arm. Because the drop-out rate in the treatment arm was much lower this will make the treatment appear more effective than the sham. It is a mistake from the authors to not consider this issue in their analysis. They don’t even mention it. One possible solution they could have used is to assume that drop-outs in the sham arm are “responders” (https://www.sciencedirect.com/science/article/pii/B9780128042175000084 ). This is the most cautious way of assessing the results but is a way of minimising the impact of the very high drop-out in the sham arm.
- Adverse events. Adverse event reporting is very important for any trial of a treatment. This is what the authors say: “Although we did not observe any serious adverse events (SAEs), it cannot be excluded that this is due to an underreporting by centres not being experienced in reporting SAEs.” Were the centres not given a clear protocol for how and when to report adverse events? Inadequate reporting of SAEs raises safety concerns about the trial.
- Contextual effects and blinding. The sham acupuncture points used in this trial were located on the leg. Yet, this was a treatment for shoulder pain. The authors provide this explanation “the further away sham points were located from verum points, the greater the observed difference between verum and sham treatment”. I would suggest that there is a very obvious explanation for this. When sham points are chosen that are nowhere near the area of the body needing treatment, this makes the sham less believable. It seems likely that many patients will realise that they are receiving the sham treatment when they need treatment for their shoulder and acupuncture needles are placed in their leg! This means the patients are effectively unblinded at this point, resulting in less contextual effects and invalidating the comparison between treatment and sham.
Professor Edzard Ernst also raised concerns about this paper after it was published, particularly focusing on the potential for the observed benefits to be down to contextual effects rather than the treatment itself.
Conclusion
There are many serious issues with this trial including with the treatment approach, inadequate blinding, analysis issues and safety concerns. The results from this study therefore shouldn’t really be used to inform treatment choices and it definitely isn’t evidence of the effectiveness of acupuncture. It’s disappointing that NICE have used such poor quality studies as a basis for their recommendations in their draft guideline on chronic pain.