After a traumatic brain injury (TBI) the risk of stroke is significantly increased. Taiwanese researchers conducted a study to find out whether acupuncture can help to protect TBI patients from stroke. They used Taiwan’s National Health Insurance Research Database to conduct a retrospective cohort study of 7409 TBI patients receiving acupuncture treatment and 29,636 propensity-score-matched TBI patients without acupuncture treatment as controls. Both TBI cohorts were followed for up to two years and adjusted for immortal time to measure the incidence and adjusted hazard ratios (HRs) of new-onset stroke.
TBI patients with acupuncture treatment (4.9 per 1000 person-years) had a lower incidence of stroke compared with those without acupuncture treatment (7.5 per 1000 person-years), with a HR of 0.59 (95% CI = 0.50-0.69) after adjustment for sociodemographics, coexisting medical conditions and medications. The association between acupuncture treatment and stroke risk was investigated by sex and age group (20-44, 45-64, and ≥65 years). The probability curve with log-rank test showed that TBI patients receiving acupuncture treatment had a lower probability of stroke than those without acupuncture treatment during the follow-up period (p<0.0001).
The authors conclude that patients with TBI receiving acupuncture treatment show decreased risk of stroke compared with those without acupuncture treatment. However, this study was limited by lack of information regarding lifestyles, biochemical profiles, TBI severity, and acupuncture points used in treatments.
I want to congratulate the authors for adding the last sentence to their conclusions. There is no plausible mechanism that I can think of by which acupuncture might bring about the observed effect. This does not mean that an effect does not exist; it means, however, that it is wise to be cautious and to not jump to conclusions which later need to be revised. The simplest interpretation, by far, of the observed phenomenon is that those patients opting to have acupuncture were, on average, less ill and therefore had a lower risk of stroke.
Having said that, the findings are, I think, intriguing enough to conduct further investigations – provided they are rigorous and eliminate the confounders that prevented this study from arriving at more definitive conclusions.
3 Responses to Does acupuncture reduce the risk of stroke after traumatic brain injury?
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This study was also discussed by Mark Crislip on the Science-Based Medicine blog a few days ago. See:
http://www.sciencebasedmedicine.org/acupuncture-vignettes/
And look for the header that says “Blind men and the elephant in the room”. This is what Dr Crislip has to say about fundamental flaws in the study:
“The acupuncture group was more likely to be on anti-coagulants, (p= 0.0003), antiplatelet drugs (p < 0.0001), and lipid lowering drugs (p < 0.0001). Seriously. The treatment group was more likely to be on stroke preventing medications yet it was the acupuncture that was responsible for fewer stokes? Because the statistics suggested it?
(…)
They had 2 possible explanations for the effects of acupuncture. The first was that acupuncture had biologic effects. I would bet against it. There is no plausible reason acupuncture could prevent stoke. The other was that patients in the acupuncture group had better care.
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Given that the acupuncture patients were more likely to be on a medical therapy that prevents strokes, that is a more likely answer.
It wasn’t the acupuncture, it was the medications.
When I first read this article and looked at the table that demonstrated the marked difference in medications in the two groups, I could not believe it. I read it over and over, thinking “no, that couldn’t be.” I could not understand how anyone could be blind to what would appear to be a simple explanation of the difference between the two groups. The most impressive example of confirmation bias I have ever seen."
I'm curious whether you agree with these conclusions, Professor Ernst.
yes, I do – except that I have seen many equally impressive examples of confirmation bias, and that the authors did include the important caveat in their conclusions.
It’s plausible that stabbing someone, even with needles, would change the blood chemistry, and clotting factors. I mean, the brain doubtless has some control over some of the parameters via the sympathetic nerve system. An animal that changes their blood chemistry to reduce bleeding when experiencing a sharp pain would probably survive over one that doesn’t.
Whether that effect would be the right kind, and last long enough to make a significant difference, I have no idea, and I agree the confounding factors here do not give confidence.
Needs a double blind test.