Research is essential for progress, and research in alternative medicine is important for advancing alternative medicine, one would assume. But why then do I often feel that research in this area hinders progress? One of the reasons is, in my view, the continuous drip, drip, drip of misleading conclusions usually drawn from weak studies. I could provide thousands of examples; here is one recently published article chosen at random which seems as good as any other to make the point.
Researchers from the Department of Internal and Integrative Medicine, Faculty of Medicine, University of Duisburg-Essen, Germany set out to investigate associations of regular yoga practice with quality of life and mental health in patients with chronic diseases. Using a case-control study design, 186 patients with chronic diseases who had elected to regularly practice yoga were selected and compared to controls who had chosen to not regularly practice yoga. Patients were matched individually on gender, main diagnosis, education, and age. Patients’ quality of life, mental health, life satisfaction, and health satisfaction were also assessed. The analyses show that patients who regularly practiced yoga had a significantly better general health status, a higher physical functioning, and physical component score on the SF-36 than those who did not.
The authors concluded that practicing yoga under naturalistic conditions seems to be associated with increased physical health but not mental health in chronically diseased patients.
Why do I find these conclusions misleading?
In alternative medicine, we have an irritating abundance of such correlative research. By definition, it does not allow us to make inferences about causation. Most (but by no means all) authors are therefore laudably careful when choosing their terminology. Certainly, the present article does not claim that regular yoga practice has caused increased physical health; it rightly speaks of “associations“. And surely, there is nothing wrong with that – or is there?
Perhaps, I will be accused of nit-picking, but I think the results are presented in a slightly misleading way, and the conclusions are not much better.
Why do the authors claim that patients who regularly practiced yoga had a significantly better general health status, a higher physical functioning, and physical component score on the SF-36 than those who did not than those who did not? I know that the statement is strictly speaking correct, but why do they not write that “patients who had a significantly better general health status, a higher physical functioning, and physical component score on the SF-36 were more likely to practice yoga regularly”? After all, this too is correct! And why does the conclusion not state that better physical health seems to be associated with a greater likelihood of practicing yoga?
The possibility that the association is the other way round deserves serious consideration, in my view. Is it not logical to assume that, if someone is relatively fit and healthy, he/she is more likely to take up yoga (or table-tennis, sky-diving, pole dancing, etc.)?
It’s perhaps not a hugely important point, so I will not dwell on it – but, as the alternative medicine literature is full with such subtly misleading statements, I don’t find it entirely irrelevant either.