Acupuncture is often recommended as a treatment for shoulder pain, but its effectiveness is far from proven. A new study has just been published; but does it change this uncertainty?
A total of 227 patients with subacromial pain syndrome were recruited to this RCT. The patients were allocated to three groups who received either A) group exercise, B) group exercise plus acupuncture or C) group exercise plus electro-acupuncture. The primary outcome measure was the Oxford Shoulder Score. Follow-up was post treatment, and at 6 and 12 months. Data were analysed on intention-to-treat principles with imputation of missing values.
Treatment groups were similar at baseline. All treatment groups demonstrated improvements over time. Between-group estimates were, however, small and non-significant.
The authors concluded that neither acupuncture nor electro-acupuncture were found to be more beneficial than exercise alone in the treatment of subacromial pain syndrome.
Well, that was to be expected!… I hear the rationalists amongst us exclaim.
Actually, I am not so sure.
One could easily have expected that the acupuncture groups (B and C) show a significant advantage over group A.
Because acupuncture is a ‘theatrical placebo’, a ritual that impresses patients and thus impacts on results, particularly on subjective outcomes like pain. If the results had shown a benefit for acupuncture + exercise (groups B and C) versus exercise alone (group A), what would we have made of it? Acupuncture fans would surely have claimed that it is evidence confirming acupuncture’s effectiveness. Sceptics, on the other hand, would have rightly insisted that it demonstrates nothing of the sort – it merely confirms that placebo effects can affect clinical outcomes such as pain.
As it turned out, however, this trial results happened to indicate that these placebo-effects can be so small that they fail to reach the level of statistical significance.
I think there is one noteworthy message here: RCTs with such a design (no adequate control for placebo effects) can easily generate false-positive results (in this case, this did not happen, but it was nevertheless a possible outcome). Such studies are popular but utterly useless: they don’t advance our knowledge one single iota. If that is so, we should not waste our resources on them because, in the final analysis, this is not ethical. In other words, we must stop funding research that has little or no chance of advancing our knowledge.