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.