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Letters and Responses |
I am left with more questions than answers, and I expect I am not alone. In our attempt to show evidence of efficacy, could we be too narrow in defining what constitutes evidence? Are we too narrow in measuring our outcomes? How much of what we observe as evidence when our patients improve might be due to a placebo effect? And how detrimental is the randomized controlled trial in identifying a placebo effect? Dr Anne Harrington of the Department of the History of Science at Harvard University suggested that only when our research began to measure very real physical effects of placebo did placebo come to be seen as a confounding variable in research.1 I contend that some cultures (eg, certain Asian cultures) tend to view nonspecific benefits as being part of the individuality of the healing process. I also would argue that some cultures do not even try to control for variables or to separate the physical from the metaphysical. Perhaps they are not driven by showing cause and effect in health care.
The National Institutes of Health is currently funding studies that are looking at the placebo effect.2 According to the Web site for the National Center for Complementary and Alternative Medicine of the National Institutes of Health (http://nccam.nih.gov/fi/concepts/rfa) there are 2 program announcements inviting applications addressing different aspects of placebo. Data have shown that patient expectation has a lot to do with outcome.3–5 Physical therapists may transfer enthusiasm to patients about the procedures that they have found helpful with other patients. It would be important to be able to identify whether this transfer of enthusiasm is, in fact, a "modality" that plays a critical role in enhancing the healing of our patients, but we have not sufficiently looked into the mechanisms that underlie the placebo response in our patients. Are these mechanisms primarily psychological? Neurological? Culturally conditioned? We need to continue expanding our views of what constitutes "evidence" and start keeping precise statistics on what are described as "nonspecific" effects.
The Philadelphia Panel's results are shocking in many ways. If we take these results as a record of the true measure of what in physical therapy constitutes "helpful help," we might reduce the musculoskeletal curriculum by two thirds. But let's not get carried away with too narrow a response to these data. Let's use this information as a way of expanding our observations of clinical efficacy and start taking into account outcomes that are not so easy to measure, such as motivation, mood, hope, belief in self, belief in the health care professional, prayer, optimism, and locus of control. Let's expand our ways of collecting data and stop denigrating research efforts other than the randomized controlled trial with placebo. The Sackett approach6 has a place, but I believe that we have lifted his criteria up so high that research has evolved too far from day-to-day clinical practice.
Professor and Associate Director/Curriculum
Division of Physical Therapy
University of Miami School of Medicine
5915 Ponce de Leon Blvd, 5th Floor
Coral Gables, FL 33146-2406
References
If Dr Davis believes that our future as a profession lies in our ability to produce placebo effects, perhaps she misses the point. Her view taken to its logical conclusion would not mean that we could, as she said, "reduce the musculoskeletal curriculum by two thirds," but rather that we could possibly eliminate this aspect of the curriculum in its entirety as we become not physical therapists but rather practitioners of "placebo enhancement." As a curriculum coordinator, Dr Davis should know that this role is not what sets us apart from other practitioners and is not seen as our raison d'être in any practice act or in any document that describes our practice (accreditation expectations, the normative model for physical therapist education, or the Guide to Physical Therapist Practice1). I believe Dr Davis' views to be unwise and reckless and, most importantly, potentially injurious to those patients who expect us to have some basis in science for our practice.
In addition, despite Dr Davis' contentions, RCTs are not the only method that can be used to document practice. I believe that Dr Davis chose to criticize an approach without offering any alternatives. I did not see any references to research that used the kinds of approaches Dr Davis seems to endorse, and I saw no reference by Dr Davis to her own contributions to the literature that she says we need. Lacking such references, I would consider her criticisms to be counterproductive. Dr Davis talks about taking into account things that are difficult to measure. Although I do not completely see their relevance to her arguments, I am shocked that she is unaware of the fact that many of these variables can be measured by existing scales developed within the very humanistic field of psychology. Because variables are difficult to measure does not mean that we can act as if there are data when, in fact, there are none. In noting that the literature is missing studies that take into account the variables Dr Davis thinks are important, she is not criticizing the Philadelphia Panel, but rather herself and her colleagues who share her beliefs. It is they who have failed to provide the evidence for the beliefs that she would like to take for granted in the absence of data.
An RCT that is designed to examine an intervention effect is designed to isolate a specific intervention. Dr Davis sees this as a terrible strategy. Knowing whether an intervention has any value arms the practitioner with knowledge about causality. This does not mean—and is not claimed by the sources cited by Dr Davis, including David Sackett—that in practice we dispense with the beneficial effects of practitioner attitude, faith of the patient, or any other potential additive benefit. Adding humanistic elements to patient care makes sense. I would argue, however, that it is important to know whether you are adding something to nothing or to a treatment that already has benefit. In addition, this is a researchable question. What can also be studied is whether bundled treatments—those, for example, that include elements that Dr Davis thinks are worthwhile—lead to better outcomes than do interventions without placebo enhancement or without other elements thought to be important by advocates of "alternative care."
Rather than bemoaning what we do not know and making a case for a unique use of the term "evidence," I would argue that it would be far more constructive to document whether there is any benefit to what Dr Davis believes are worthwhile additions to practice. If Dr Davis believes that in physical therapy enhanced outcomes occur with certain additions to care, then it is time for those who take views similar to those of Dr Davis to actually provide data. I believe that views such as those expressed by Dr Davis could enrich the profession. There is room, even need, for differeing views and dissent. If, however, there is no effort to be more scientific in expressing those views and no effort to use existing literature when expressing those views, few things could be more harmful. Similarly, I believe the profession is harmed when anyone consistently expresses dissenting views but makes no contribution to our scientific basis through peer-reviewed publication, because then their dissent remains baseless in fact and sustained only by bias.
References
As expected, we are now seeing Letters to the Editor in Chief that point out the omission of manual therapy treatments. Unfortunately, the letter from Flynn et al intimates more than a methodological disagreement, however, and appears to question the motives of the authors as well as those of the Editor in Chief and Guest Editor. I would call particular attention to the statement, "Is it little wonder that physical therapists use these interventions at lower-than-expected rates when our own reviews fail to include these interventions?" Do I really need to remind Flynn and colleagues that no profession can claim ownership to any manuscript printed in the Journal? Dr Davis focuses most of her attention on an apparent lack of accounting for placebo effects in the literature reviewed by the Philadelphia Panel. She goes on to point out possible funding sources for those interested in studying placebo effects. I can see no reason why such funding cannot be sought by those physical therapists interested in studying the effects on outcome attributable to issues such as patient expectations.
Yes, the Philadelphia Panel had a narrow scope of literature to review, which Flynn and colleagues translate as "deliberately" leaving out manual therapy articles from their systematic review. Rather than question the panel's motives, the editorial process, or, in the case of Dr Davis, the inadequacy of research methods, I would ask the authors the following questions:
Where in the October issue does it specifically state that the articles reviewed represent an exhaustive evaluation of all physical therapy interventions for back, neck, shoulder, and knee pain?
What stops others from adding to our scientific body of knowledge: (1) with another systematic review that includes treatments that were not included in the Philadelphia Panel's contribution or (2) with publications that differentiate placebo versus other effects of physical therapy interventions?
With regard to the first question, we do our readership a disservice to assume, as Flynn and colleagues state, that "many Journal readers may not be familiar" with evidence in favor of manual therapy for treatment of lumbar spine conditions. With regard to the second question, I can see no reason why another publication using similar methods and including studies of manual therapy treatments would not be an acceptable and welcome follow-up that would be a supplement to the October publication. Similarly, studies that accurately differentiate the physical and psychological effects of interventions and explain these effects within a sound theoretical framework would greatly enhance our understanding of physical therapist practice.
As "dedicated advocates of evidence-based practice," Flynn and colleagues should realize that the most constructive response to a publication in which the method or scope is questioned is an additional publication that adds to the body of evidence as a whole. Dr Davis, who has long been an advocate of complementary treatment methods, contends that studies focusing on physical versus placebo effects of physical therapy interventions would be welcome additions to our scientific body of knowledge. I would agree with her contention and would welcome such publications, regardless of the research methods used. I would contend that, in future qualitative reviews of the literature, such publications would be much more difficult to ignore than letters to the editor.
Department of Physical Therapy
University of Pittsburgh
Forbes Tower, Room 6035
Pittsburgh, PA 15261
(delitto{at}pitt.edu)
References
We will discuss the comments in detail in order to provide our readers with the best response based on the best evidence that we have available to us. Regarding the comments suggesting that we did not mention physical therapy interventions, it was not our intention to present the whole spectrum of interventions practiced in physical rehabilitation. It is explicitly noted in our articles and reflected in the titles ("selected interventions") that we were including only physical rehabilitation interventions.
We would like to clarify that we excluded manual therapy from our review for several reasons:
We agree with the letter writers that teaching in an evidence-based practice framework is extremely important. We would like to note, however, that there might be some potential publication bias in the references on manual therapy that have been suggested by the letter writers. For example, the referenced articles are not all systematic reviews or meta-analyses, and often the methodology used for development of CPGs is a descriptive approach and expert opinion only, not a quantitative approach. Other well-established meta-analyses and CPGs obtained different results on manual therapy than those obtained by the cited studies.
As contributors to the Users' Guides to the Medical Literature: A Manual for Evidence-Based Clinical Practice,9 we promote the importance of using rigorous methodology in the effort to provide physical therapists with strong and valid conclusions about the efficacy of their interventions in daily practice. We certainly invite the physical therapy community to apply rigorous methodology to the existing literature on efficacy of manual therapy and manipulation to derive evidence-based approaches.
In an attempt to examine the efficacy of manual therapy and manipulation, we found that extensive literature already exists.2,10–,22 However, the efficacy of these specific interventions for certain conditions, especially for low back pain, seemed to be controversial, and conflicting evidence exists. Many systematic reviews and CPGs have already been published on manual therapy/manipulation efficacy.1–,7 Furthermore, they all conclude that there is insufficient evidence or conflicting evidence regarding acute and chronic low back pain.
We hope our articles will provide the reader with some guidance in clinical decision making regarding selection of intervention. We have noted above the potential publication biases, which can and do exist in the literature. According to the most recent systematic reviews, there is no clear evidence for all of the clinical applications of manual therapy and manipulation. As we have written in the methods article published alongside the results of the review, "The following interventions were excluded due to either a sufficient body of knowledge or less frequent use: manipulation, manual therapy, swimming exercise, phonophoresis, etc..."
We have gone to extreme lengths to try to avoid publication bias in the interventions we have chosen to study. Regarding the interventions on which we were not asked to conduct systematic reviews, we would be happy to discuss with the letter writers and the authors of previously conducted and published systematic reviews and guidelines whether there is a need for updating these resources in order for clinicians who rely on the best available evidence to make clinical decisions about health care.
We have followed the Cochrane Collaboration methodology and have involved multiple partners, such as the CIGNA Foundation, a large multidisciplinary team, a consensus panel, and patient partners. When readers review the methodology to determine their use of this evidence in making health care decisions, we ask that they be the judge. Our hope is that readers will review our methodology and consider the use of the evidence in making health care decisions about the interventions that were included in our review.
The Philadelphia Panel
References
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