Taking part in acupuncture trials changes the treatment.

In an earlier post I wrote about how the placebo effect of acupuncture can be improved by the behaviour of the acupuncturist(s).  I have now come across a study which shows that taking part in an acupuncture trial changes the expectations and behaviour of participants and influences how the intervention is delivered and experienced.  This  change is such that the placebo effect is negatively affected, suggesting that such trials are under-reporting the positive benefits of properly delivered traditional acupuncture.

The Study

In a qualitative study, 10 participants enrolled in a randomised controlled trial, which compared acupuncture for migraine against sham (pretend), were interviewed twice in a semi-structured manner.  The researchers found that the practitioner and most participants actively ‘played their part’ in the trial, taking on research roles that differed from their usual roles of ‘patient’ and ‘doctor’.  There was a reduction in talking, explanations and participation, and treatment was focused on the migraine to the exclusion of other conditions, even if the participants considered them to be a cause of the migraine.

Study conclusions

The authors concluded that treatment in the trial differed from ‘real life’ traditional acupuncture, and that these differences affected needling (the specific intervention being studied) as well as contextual factors. They further concluded that this trial design limitation appears to be inevitable when a sham-controlled design is used to study an intervention based on a holistic and participative treatment strategy.  They warn that these findings should be taken into account in the design and interpretation of RCTs of complex interventions such as acupuncture.

“Playing their parts”: the experiences of participants in a randomized sham-controlled acupuncture trial. J Altern Complement Med. 2008 Mar; 14(2):199-208).