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Evidence-Based Practice and Physical Therapy

During his address to congress on behalf of people with disabilities, Michael J. Fox said that if you ask a person what their favorite therapy is, they will tell you it is the one that works. Using interventions that work is what evidence-based practice (EBP) is all about. It is not a particularly new concept, as David Sackett originally proposed it for medicine in the early 1990s. Since that time, over 1,000 articles on this topic have been published in medical journals. To quote Sackett, "Evidence-based medicine (EBM) is the integration of best research evidence with clinical expertise and patient values" (Sackett et al., 2000). Importantly, this definition states that clinical decision-making should be based on three components: research, clinical expertise, and patient values. Thus, it is not solely driven by research studies, but also values clinical expertise and the wishes of the patient and family when determining optimal interventions. Furthermore, this definition acknowledges that not all research evidence is equal, and that some research studies should be given greater consideration than others when evaluating therapeutic regimens.

The philosophy of EBM is also relevant to other health care fields, including physical therapy, and in order to be more inclusive, is now often referred to as evidence-based practice (EBP). EBP has generally, although not universally, been endorsed by health care professionals for two major reasons. First, there has been an explosion in information, with a ten-fold increase in professional journals between 1940 and 1993 (Presidentís IT Advisory Committee Interim Report, 1998). At this time, there are more than 23,000 biomedical journals. Second, rapid advances have occurred in information technology over the last decade. In 1997, over 100 million people were using the Internet worldwide, a number that is expected to increase to more than 1 billion by 2005 (Presidentís IT Advisory Committee Interim Report, 1998). Since increasing numbers of biomedical journals can be accessed via the Internet, this has greatly increased the accessibility to research evidence for both clinicians and clients. However, the amount and availability of information can also be daunting. Therefore, guidelines on ways to evaluate the evidence have generally been welcomed. Other reasons for endorsing EBP are the concern that the traditional approach of relying on continuing education courses for keeping clinical knowledge and practice up-to-date does not lead to improvements in clinical performance (Davis, et al., 1999), and the need for greater accountability for reimbursement and liability.

EBP is a five-step process (Sackett et al., 2000). Step 1 is to convert the need for information into a clinically relevant, answerable question. What exactly is it that you want to know? One method for formulating the question is referred to as PICO. P refers to the patient or population of interest, I to the intervention, C to the comparison intervention (if one exists), and O to the outcome. An example of how to use the PICO method to refine a question regarding the role of exercise for certain clinical problems is shown below.

P     What individual or patient populations do I have in mind?

            People with post-polio syndrome.

I     What type of exercises am I considering?

            Strength training.

C     How does my intervention compare to the effects of another intervention? What is that other intervention?

            Relaxation exercises.

O     What are the goals of the exercise intervention?

            Increased daily activity level.

Putting this all together results in a more refined question. "For clients with post-polio syndrome, is strength training better than relaxation exercises for increasing levels of daily physical activity?"

Step 2 is to efficiently find the best evidence. This step is often easier said than done, but all things considered, the Internet has greatly increased the ease with which many clinicians can access and rapidly sort current information. Of the numerous databases available for information, a few are particularly relevant to physical therapy. PubMed is probably the best known database. It is maintained by the National Library of Medicine and is free to the public at http://www.ncbi.nlm.nih.gov/PubMed. Most searches should begin by looking at what is available through PubMed. PubMed allows you to search combinations of key words, such as physical therapy and post-polio syndrome. Depending upon the number of articles retrieved with these key words, one can either expand or narrow the search by removing or adding key words. A search can also be narrowed by limiting it to certain dates, e.g., after 1995, or by types of articles, e.g., review articles. It is not unusual for an initial search to yield thousands of articles, but with further refinement to be reduced to only a few highly relevant ones.

Citations in Nursing and Allied Health (CINAHL) is a database targeting health professionals in these disciplines. Whereas articles on biomedical topics are the primary ones found in PubMed, CINAHL will often include citations covering a broader scope, e.g., special education or physical fitness. Go to http://www.cinahl.com/index.html to access this database. The Cochrane Library is another useful database. It includes some excellent reviews of the current available research on selected medical topics. The address is http://www.cochranelibrary.com/clibhome/clib.htm. Abstracts can be accessed at no charge. The Physiotherapy Evidence Database (PEDro) is designed specifically for physical therapy. The address is http://ptwww.fhs.usyd.edu.au/pedro/. Tips for searching the literature are also available at http://cebm.jr2.ox.ac.uk.

The APTAís Hooked on Evidence Initiative is a new and exciting grass roots effort to systematically find and evaluate research with relevance to physical therapy practice. This effort wasinitiated by the California Research Special Interest Group and has now been extended nationally. People willing to find and review articles are needed. More information about the process involved is available on their website, which can be accessed from the APTA website or https://www.apta.org/hookedonevidence/index.cfm.

Step 3 is to critically appraise the evidence. Surprisingly, there are only three critical questions that you need to ask to appraise most clinical studies. Is the study valid? Are the findings clinically important? Do the findings apply to my client? However, answering each of these three questions requires a systematic analysis. Indeed, a series of factors needs to be considered when appraising the validity, such as was the study retrospective or prospective? Was it randomized? Did it use human or animal subjects? Depending upon the answers to these and other questions, the validity of the evidence, or in other words, how close it is to the truth, is ranked. To appraise the clinical importance of the evidence one needs to consider the magnitude of the effect of the intervention, as well as the probability of the effect generalizing to whole patient populations. To appraise the applicability of the findings, you must compare your client to the subjects used in the study, consider the feasibility and risks and benefits of the intervention, and also determine if it is in line with the clientís preferences. Mastery of step 3 is beyond the scope of this article, but additional information is available on the web at http://cebm.jr2.ox.ac.uk and http://www.fhs.mcmaster.ca/rehab/ebp/.

Step 4 involves applying critically appraised evidence to clinical practice. Of all the steps, this is the one that may be the most difficult. Numerous challenges face health care providers interested in changing their clinical practice based on EBP. These challenges include, but are not limited to, a lack of control over their workload, competing priorities, limited access to the Internet and/or journals, lack of training in information technology and critical appraisal of literature, and a lack of institutional support for EBP. To overcome these obstacles, it helps to remember the ancient proverb, "A journey of a thousand miles begins with one step." Start small. Form a lunchtime journal club to critically appraise relevant clinical studies. Be a "clinician-scientist" by using valid and reliable tests and measures to acquire baseline measurements and evaluate outcomes of your clients. Search for a topic of interest on PubMed or another database. Be part of the APTA Hooked on Evidence Initiative. These are just a few of many possible ways to begin to integrate EBP into clinical practice.

Step 5 is to evaluate the effects of EBP on clinical outcomes. Whether incorporating EBP into physical therapy practice will increase the likelihood that Michael J. Fox and all of our other clients receive interventions that are effective is unknown. The essence of EBP is an argument for critical appraisal of therapeutic interventions. Wisely, the people who developed EBP extended this requirement not only to clinical interventions, but also to EBP itself. Future studies are needed to determine if there is a correlation between the integration of EBP into clinical practice and improvements in outcomes.

In conclusion, EBP is a five-step process that aims to improve health care outcomes by balancing findings from research with clinical experience and patient/family preferences. Extensive information on EBP is available both in print and online. Additional information on how to incorporate EBP into physical therapy practice was presented at the Fall 2002 PTWA Conference. We have the technology for EBP. We have the intelligence to critically appraise evidence. The time is right to incorporate EBP into physical therapy practice.


1. Davis D, OíBrien MA, Freemantle N, Wolf FM, Mazmanian P, Taylor-Vaisey A., 1999, Impact of formal continuing medical education: do conferences, workshops, rounds, and other traditional continuing education activities change physician behavior or health care outcomes? JAMA.282:867-74.

2. Presidentís IT Advisory Committee Interim Report, August 1998.

3. Sackett, DL, Straus, SE, Richardson, WS, Rosenberg, W, Haynes, RB, 2000, Evidence-Based Medicine. How To Practice and Teach EBM. 2nd edition. Churchill Livingtone, NY.

Ramona Hicks, PhD, PT and
Jeff Coppersmith, MS, PT

Evidence-Based Practice Resources


APTAís Hooked on Evidence Initiative
"The contents of this site provide learning tools to foster evidence based practice in physical therapyÖ."

Centre for Evidence-Based Medicine at Oxford University, London, England
A lot of the original work and dissemination of information about EBP can from this group of physicians and scientists. It is an excellent site and contains current references on the theory and methodology of EBP, as well as a substantial annotated list of Internet sites. It also contains tutorials and practical guidelines for incorporating EBP into clinical practice.

Occupational Therapy Evidence-Based Practice Research Group
This site has great links to guidelines and forms for critical analysis of research.

Netting the Evidence: Links to evidence-based practice sources
This site has a comprehensive list of annotated evidence-based research Internet sites.

Evidence Based Health Care - Latest Articles
"The New York Academy of Medicine in partnership with the Evidence-based Medicine Committee of the American College of Physicians, New York Chapter has received a grant from the National Institutes of Health to develop an Evidence-based Medicine Resource Center." This site may offer some advantages over the Centre for Evidence-Based Medicine at Oxford University for members of PTWA because it is located in the USA.

The Dartmouth Atlas of Health
" The Dartmouth Atlas project brings together researchers in diverse disciplines - including epidemiology, economics, and statistics - and focuses on the accurate description of how medical resources are distributed and used in the United States. " This is an interesting site and reinforces the need for systematic analysis of the risks and benefits of various medical and health care interventions.

Web databases

University of Washington Library Gateway (Click on Find It to get to databases)

PubMED: MEDLINE of the National Library of Medicine: free to the public
The largest database of publications on medicine and health care. Free and available to the public. Includes a tutorial (which is highly recommended) on how to use it to optimize your searches.

CINAHL Citations in Nursing and Allied Health Literature
This database often includes publications not on PubMed, but with high relevance to physical therapy. Requires a site license, which can be for an individual or group.

Cochrane Library
The Cochrane Library is an electronic publication that contains systematic overviews of the effects of health care. Provides free access to abstracts. The Cochrane Library is an invaluable source of review articles on important topics, however often they are more closely linked to medicine, rather than to physical therapy. In the future, the APTA Hooked on Evidence Initiative may provide a similar source of information, but with a focus on topics directed toward physical therapy.

PEDro: The Physiotherapy Evidence Database of The Centre for Evidence-Based Physiotherapy, School of Physiotherapy, University of Sydney Australia.
or via
Designed for physical therapists, access to biblographic data, abstracts, and systematic reviews of the literature. Includes a tutorial.




Print Sources
  • Garrard, J. Health Sciences literature review made easy: The matrix method. Gaithersburg, MD: Aspen; 1999.
  • Harris SR. How should treatments be critiqued for scientific merit? Physical Therapy 76:175-181; 1996.
  • Law, M. Evidence-based rehabilitation: A guide to practice. Thorofare, JN: Slack; 2002.
  • Sackett, DL, Strauss SE Richardson WS, Rosenberg W, Hayes RB. Evidence-based medicine: how to practice and teach EBM. 2nd ed. New York: Churchill Livingstone; 2000.
  • Tonelli, M. The philosophical limits of evidence-based medicine. Academic Medicine. 73: 1234-1240;1998.
  • Also see Evidence-Based Medicine for a list of current and up-dated references on the theory and methodology of EBP.
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    Last modified: November 30, 2007