When Moyer presented the data that he and his team had gathered that reviewed 19 qualified studies with a total of 704 participants (614 adults), the data points stretched across the table. Dots with long black horizontal lines that often cross the vertical dotted line (the mean) that tells us how strong or weak the effect of the treatments were. This brought some “Hmmm” and slight smiles among the registered massage therapists (RMTs) who may find this as enlightening as finding out that some Costcos open at nine in the morning.
Massage research is still quite low in quantity and quality compared to physical therapy and nursing, and it still runs into many problems that other healthcare professions face. As Moyer had presented, we should not take what we read for its face value, and we should critically appraise research within and without our field. So what should we consider when we read research, especially in manual therapy?
Although massage research is still low in quantity and quality compared to physical therapy and nursing, it still runs into many problems that other healthcare professions face. As Moyer had presented, we should not take what we read for its face value, and we should critically appraise research within and without our field. So what should we consider when we read research?
Why Should We Care?
A while back, I read an editorial published in the British Journal of Sports Medicine (BJSM) regarding why physical therapists need to adopt a strong and honest evidence-based practice to avoid misleading the public and to draw attention to interventions that has a strong base of scientific evidence and efficacy. The authors gave an example where patients with acute low back pain should get physical therapy first as the first line of defense, but this statement from the American Physical Therapy Association (APTA) is not backed up by sound evidence. In fact, they cited that such endorsements ignored “high-quality evidence that early physical therapy is more costly and provides no benefit over usual care of LBP,” and “low-quality evidence that early physical therapy likely results in higher rates of opioids, imaging, injections, and surgery compared with no physical therapy.”4
Misleading the public can deepen the stereotypes and promote a negative criticism of our profession in their eyes. Therefore, understanding research and watching out for false claims can initially improve what we market and say to our clients and patients. However, with so many flaws and conflicting information in the scientific process—never mind fake news and clickbaits—where do we start to disseminate what is good, poor, and everything in between?
“I recently heard a man interviewed on my local public radio station complain about the difficulty of keeping up with what he called the ‘swerves of scientific wisdom’: ‘I spent two tours in Iraq as a gunner,’ he said, ‘and I know how hard it is to hit a moving target. I wish these scientific experts would just hold still.’
“But that’s the thing. Holding still is exactly what science won’t do.”
~ David P. Barash, evolution biologist and psychology professor at the University of Washington 5
1. Prior plausibility: Does the research make sense with what we already know about the material world (e.g. chemistry, physics, biology, psychology)?
If your mom told you that a large shark had attacked her boat while she went fishing, and there is damage to the hull and you know the waters where she fished is home to sharks, then you would probably believe her. But if she told you that a two-headed sea serpent had attacked her and showed you the same evidence, you would probably ask for more evidence.
This is basically what prior plausibility implies: how valid is a claim based on the existing body of knowledge? In that example, do two-headed sea serpents exist given what we know about marine biology and paleontology?
Our understanding of the natural world and the universe comes from several centuries of observations and experiments that evolved in small increments. Even though these changes can sometimes overturn established facts (e.g. number of planets in the solar system, primates do not have empathy or use tools), new theories are still based on the fundamental principles of physics, chemistry, biology, and other natural sciences. We cannot coin up an idea out of thin air and establish it as a fact (and sell it!) if it contradicts the existing body of knowledge. To do so, we would need an immense amount of data that overturns the existing knowledge.
“The amount of evidence necessary to add one small bit of incremental understanding about a phenomenon is much less (and should be less) than the amount of evidence necessary to entirely overturn a well-established theory,” neurologist Steven Novella had explained on his blog when someone criticized the application of prior plausibility in medicine.
“Another way to look at it is this: the amount of evidence necessary to overturn an established conclusion is proportional to the amount of evidence that established the conclusion in the place. Failing to consider prior probability would also mean overturning a mountain of prior evidence with one tiny new bit of evidence. This amounts to favoring the new evidence simply because it is the most recent, but there is no justification for this approach.”6
Sidebar: Science-based or Evidence-based?
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