Rheumatology Advance Access originally published online on December 13, 2005
Rheumatology 2006 45(2):125; doi:10.1093/rheumatology/kei256
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EDITORIAL |
Testing acupuncture for osteoarthritis: pragmatic trials or efficacy studies?
Complementary Medicine, Peninsula Medical School, Universities of Exeter and Plymouth, 25 Victoria Park Road, Exeter EX2 4NT, UK
Correspondence to: Edzard.Ernst{at}pms.ac.uk
In this issue, Linde et al. [1] report the results of a study that is amongst the largest clinical investigations of acupuncture ever conducted. Its results suggest that patients suffering from osteoarthritis respond remarkably well to acupuncture treatment. This paper deserves both careful consideration and critical comment.
This pragmatic study, as the authors call it, is part of an even larger project. It was initiated because German health insurances felt that, on the basis of the evidence, it was debatable whether they should continue to pay for the cost of acupuncture. After lengthy discussions, it was decided that, at least for a while, it would remain a refundable treatment, provided the physician asking for refunds was a participant in a nationwide evaluation process. This unusual situation explains why about 10 000 doctors volunteered to take part and why patient numbers were initially astronomical (about 500 000).
It is important to understand this background because it has the potential to impact significantly on the findings of this study. Linde et al. state that ‘the minimal interference of the study with routine practice makes it likely that the findings reflect current practice in Germany’ [1]. I am not convinced that this is true. The treatment may well reflect current practice but the socio-economic situation surely did not. Participating doctors as well as patients knew that the results of these evaluations would determine whether or not acupuncture would be refunded in future. It is, I think, unlikely that their judgements regarding the effects of acupuncture were not influenced by this knowledge.
One strength of pragmatic studies, conventional wisdom tells us, is their high external validity—they depict real life and should therefore be generalizable [2]. However, mimicking real life could turn out to be a problem if real life changes (which it frequently does). ‘Alternative’ treatments like acupuncture can quickly go in or out of favour with an often gullible public. They are also prone to considerable national differences. What is true today may not be true tomorrow and what works in Germany may not work in the UK. Thus, the results of pragmatic trials may be far less generalizable than conventional wisdom has it, particularly in the area of alternative or other fashionable treatments.
The question arises what the study by Linde et al. [1] really shows. It demonstrates exactly what the authors conclude: clinical improvement was reported by patients with osteoarthritis after acupuncture (one should add: under the very special conditions that existed at the time in Germany and that are unlikely to ever be re-created). It does not, however, show that acupuncture caused this improvement. The positive outcome could be due to placebo or Hawthorn effects, to concomitant therapies, to regression towards the mean or simply to patients trying to please their doctors. Moreover, the results do not tell us much about what type of acupuncture helped which type of osteoarthritis. Pragmatic clinical trials tend to be all-inclusive and therefore specific questions can often not be answered.
Yet the results of Linde et al. [1] do carry some weight, not least because they are partly supported by those of a randomized trial from the same national evaluation process [3]. But how should we explain the finding that the long-term results were positive in the observational study [1] while they were negative in the randomized trial [3]?
‘Give me an efficacy study any time’, I am tempted to exclaim at this point. But this would probably be quite wrong. The question rarely is whether we need pragmatic or efficacy trials. They are not like fire and water, but trials move on a continuum from the strictly controlled conditions of the laboratory to the confounded situation of real life. Therefore they answer different research questions and, in an ideal world, we should have both to guide our decisions. The study by Linde et al. [1] does generate a host of fascinating results. What seems crucial, however, is to interpret its results correctly. We should commend Linde and colleagues for repeatedly pointing out that the interpretation of their data requires great caution.
The author has declared no conflicts of interest.
References
- Linde K, Weidenhammer W, Streng A, Hoppe A et al. Acupuncture for osteoarthritic pain. Rheumatology 2005;45:222–7.[Medline]
- Roland M, Torgerson DJ. What are pragmatic trials? BMJ 1998;31:285.
- Witt C, Brinkhaus B, Jena S et al. Acupuncture in patients with osteoarthritis of the knee: a randomised trial. Lancet 2005;366:136–43.[CrossRef][Web of Science][Medline]
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