Craniosacral therapy is effective for treating chronic pain … but only if one completely ‘forgets’ to think critically

I have been sceptical about Craniosacral Therapy (CST) several times (see for instance here, here and here). Now, a new paper might change all this:

The systematic review assessed the evidence of Craniosacral Therapy (CST) for the treatment of chronic pain. Randomized clinical trials (RCTs) assessing the effects of CST in chronic pain patients were eligible. Pain intensity and functional disability were the primary outcomes. Risk of bias was assessed using the Cochrane tool.

Ten RCTs with a total of 681 patients suffering from neck and back pain, migraine, headache, fibromyalgia, epicondylitis, and pelvic girdle pain were included.

Compared to treatment as usual, CST showed greater post intervention effects on:

• pain intensity (SMD=-0.32, 95%CI=[−0.61,-0.02])
• disability (SMD=-0.58, 95%CI=[−0.92,-0.24]).

Compared to manual/non-manual sham, CST showed greater post intervention effects on:

• pain intensity (SMD=-0.63, 95%CI=[−0.90,-0.37])
• disability (SMD=-0.54, 95%CI=[−0.81,-0.28]) ;

Compared to active manual treatments, CST showed greater post intervention effects on:

• pain intensity (SMD=-0.53, 95%CI=[−0.89,-0.16])
• disability (SMD=-0.58, 95%CI=[−0.95,-0.21]) .

At six months, CST showed greater effects on pain intensity (SMD=-0.59, 95%CI=[−0.99,-0.19]) and disability (SMD=-0.53, 95%CI=[−0.87,-0.19]) versus sham. Secondary outcomes were all significantly more improved in CST patients than in other groups, except for six-month mental quality of life versus sham. Sensitivity analyses revealed robust effects of CST against most risk of bias domains. Five of the 10 RCTs reported safety data. No serious adverse events occurred. Minor adverse events were equally distributed between the groups.

The authors concluded that, in patients with chronic pain, this meta-analysis suggests significant and robust effects of CST on pain and function lasting up to six months. More RCTs strictly following CONSORT are needed to further corroborate the effects and safety of CST on chronic pain.

Robust effects! This looks almost convincing, particularly to an uncritical proponent of so-called alternative medicine (SCAM). However, a bit of critical thinking quickly discloses numerous problems, not with this (technically well-made) review, but with the interpretation of its results and the conclusions. Let me mention a few that spring into my mind:

1. The literature searches were concluded in August 2018; why publish the paper only in 2020? Meanwhile, there might have been further studies which would render the review outdated even on the day it was published. (I know that there are many reasons for such a delay, but a responsible journal editor must insist on an update of the searches before publication.)
2. Comparisons to ‘treatment as usual’ do not control for the potentially important placebo effects of CST and thus tell us nothing about the effectiveness of CST per se.
3. The same applies to comparisons to ‘active’ manual treatments and ‘non-manual’ sham (the purpose of a sham is to blind patients; a non-manual sham defies this purpose).
4. This leaves us with exactly two trials employing a sham that might have been sufficiently credible to be able to fool patients into believing that they were receiving the verum.
5. One of these trials (ref 44) is far too flimsy to be taken seriously: it was tiny (n=23), did not adequately blind patients, and failed to mention adverse effects (thus violating research ethics [I cannot take such trials seriously]).
6. The other trial (ref 41) is by the same research group as the review, and the authors award themselves a higher quality score than any other of the primary studies (perhaps even correctly, because the other trials are even worse). Yet, their study has considerable weaknesses which they fail to discuss: it was small (n=54), there was no check to see whether patient-blinding was successful, and – as with all the CST studies – the therapist was, of course, no blind. The latter point is crucial, I think, because patients can easily be influenced by the therapists via verbal or non-verbal communication to report the findings favoured by the therapist. This means that the small effects seen in such studies are likely to be due to this residual bias and thus have nothing to do with the intervention per se.
7. Despite the fact that the review findings depend critically on their own primary study, the authors of the review declared that they have no conflict of interest.

Considering all this plus the rather important fact that CST completely lacks biological plausibility, I do not think that the conclusions of the review are warranted. I much prefer the ones from my own systematic review of 2012. It included 6 RCTs (all of which were burdened with a high risk of bias) and concluded that the notion that CST is associated with more than non‐specific effects is not based on evidence from rigorous RCTs.

So, why do the review authors first go to the trouble of conducting a technically sound systematic review and meta-analysis and then fail utterly to interpret its findings critically? I might have an answer to this question. Back in 2016, I included the head of this research group, Gustav Dobos, into my ‘hall of fame’ because he is one of the many SCAM researchers who never seem to publish a negative result. This is what I then wrote about him:

Dobos seems to be an ‘all-rounder’ whose research tackles a wide range of alternative treatments. That is perhaps unremarkable – but what I do find remarkable is the impression that, whatever he researches, the results turn out to be pretty positive. This might imply one of two things, in my view:

• all alternative therapies are effective,
• the ‘Trustworthiness Index’ of Prof Dobos is unusual.

I let my readers chose which possibility they deem to be more likely.