Two articles on PainSci cite Power 2011: 1. Massage Therapy Kinda, Sorta Works for Back Pain 2. Placebo Power Hype
PainSci notes on Power 2011:
This paper is particularly interesting for its explanation of the “frustrebo” effect: “Negative true placebo effects (‘frustrebo effects’) in the comparison group, and cognitive measurement biases in the comparison group and the experimental group make the non-specific effect look like a benefit for the intervention group.” (A particularly excellent example of the frustrebo effect can be seen in Cherkin et al.)
original abstract †Abstracts here may not perfectly match originals, for a variety of technical and practical reasons. Some abstacts are truncated for my purposes here, if they are particularly long-winded and unhelpful. I occasionally add clarifying notes. And I make some minor corrections.
When people who advocate integrating conventional science-based medicine with complementary and alternative medicine (CAM) are confronted with the lack of evidence to support CAM they counter by calling for more research, diverting attention to the 'package of care' and its non-specific effects, and recommending unblinded 'pragmatic trials'. We explain why these responses cannot close the evidence gap, and focus on the risk of biased results from open (unblinded) pragmatic trials. These are clinical trials which compare a treatment with 'usual care' or no additional care. Their risk of bias has been overlooked because the components of outcome measurements have not been taken into account. The components of an outcome measure are the specific effect of the intervention and non-specific effects such as true placebo effects, cognitive measurement biases, and other effects (which tend to cancel out when similar groups are compared). Negative true placebo effects ('frustrebo effects') in the comparison group, and cognitive measurement biases in the comparison group and the experimental group make the non-specific effect look like a benefit for the intervention group. However, the clinical importance of these effects is often dismissed or ignored without justification. The bottom line is that, for results from open pragmatic trials to be trusted, research is required to measure the clinical importance of true placebo effects, cognitive bias effects, and specific effects of treatments.
This page is part of the PainScience BIBLIOGRAPHY, which contains plain language summaries of thousands of scientific papers & others sources. It’s like a highly specialized blog. A few highlights:
- No long-term effects after a three-week open-label placebo treatment for chronic low back pain: a three-year follow-up of a randomized controlled trial. Kleine-Borgmann 2022 Pain.
- Exercise and education versus saline injections for knee osteoarthritis: a randomised controlled equivalence trial. Bandak 2022 Ann Rheum Dis.
- Association of Lumbar MRI Findings with Current and Future Back Pain in a Population-based Cohort Study. Kasch 2022 Spine (Phila Pa 1976).
- A double-blinded randomised controlled study of the value of sequential intravenous and oral magnesium therapy in patients with chronic low back pain with a neuropathic component. Yousef 2013 Anaesthesia.
- Is Neck Posture Subgroup in Late Adolescence a Risk Factor for Persistent Neck Pain in Young Adults? A Prospective Study. Richards 2021 Phys Ther.