WHERE IS OF REHABILITATION PLACED IN THE WORLD-WIDE TREND TOWARDS EVIDENCE BASED HEALTH CARE?
World-wide, collaborative efforts to develop databases of information are mushrooming. Of recent origin is the availability of information on 'evidence based health care', which can be defined as information on current best evidence in making decisions about the care of ill persons. This article gives an introduction to the basic strategies for practising evidence based health care. Such information is increasingly available to everyone who has access to Internet, regardless of where they live or work.
TRADITIONAL HEALTH CARE VS. EVIDENCE BASED HEALTH CARE
Traditionally, decisions in health care have been based on expert opinions. In the traditional expert opinion approach, clinical decision-making derives from an authority system in which the opinion of a teacher or mentor, a very experienced clinician, a chapter in a textbook, or the recommendations of a consensus panel are the main sources of guidance. While this type of system provides valuable information, the problem with it is that opinions of authorities, though conscientious, are not always right. For example, one landmark study compared treatments for myocardial infarction from 1966 to 1992 as recommended in review articles and textbooks, versus the results of randomised controlled trials. Recommendations of cardiology authorities lagged far behind scientific evidence. Thirteen years after studies showed that thromblytics significantly reduced mortality from myocardial infarction, only 51% of the review articles and texts recommended their use. A full decade after clear proof that thrombolytics save lives, the majority of authorities in the field of cardiology were still calling thrombolytics experimental-and this had a dampening effect on the use of this life-saving therapy.
Another common source of clinical guidance is expert or consensus panels. This is a committee of experts who reach a consensus, based on their best judgement, on a specific issue, such as the treatment of a disease. Although such panels have the advantage of speed and the name recognition of expert members, it cannot be known what level of empirical evidence, if any, is supporting their recommendations. Consensus in no way implies accuracy. Six hundred years ago, an expert panel would have agreed that the world was flat. An expert panel at the turn of the century would have recommended bloodletting to control seizures. Expert panels once recommended that physicians measure urinary estriol excretion of pregnant women to assess foetal health. The test was awkward and difficult for patients but was widely used, even though there was no evidence that it could lower perinatal mortality. Ultimately, the test was shown to be worthless.
Evidence based health care differs from traditional practice in that it emphasises scientific results, not expert opinions. Evidence based health care arose in response to concerns about the appropriateness of care. It is also a response to ongoing concerns about troubling variations in care that result from the traditional expert opinion approach. We see these variations -individual, institutional, and regional variations-in diagnostic testing, hospitalisation rates, therapeutic interventions and in outcomes.
EVIDENCE BASED HEALTH CARE: WHAT IS IT?
Evidence based health care is defined as the "conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients. The practice of evidence based health care means integrating individual clinical expertise with the best available external clinical evidence from systematic research." By individual clinical judgement is meant the proficiency and judgement that individual clinicians acquire through clinical experience and practice. Increased expertise is reflected in many ways, but especially in more effective and efficient diagnosis and in the more thoughtful identification and compassionate use of individual patient's predicaments, rights and preferences in making clinical decisions about their care. By best available external evidence is meant clinically relevant research, often from the basic sciences of medicine, but especially from patient-centred clinical research into the accuracy and precision of diagnostic tests, the power of prognostic markers, and the efficacy and safety of therapeutic, rehabilitative and preventive regimens. Good clinicians use both individual clinical expertise and the best available external evidence and neither alone is enough.
THREE STRATEGIES FOR PRACTISING EVIDENCE BASED HEALTH CARE
There are three basic strategies for practising evidence based health care: 1) conducting one's own search and critical appraisal of evidence to answer a specific clinical question; 2) seeking evidence based medical summaries to extract information that applies to one's individual patients; and/or 3) accepting evidence-based practice guidelines developed by one's colleagues.
- 1. Conducting one's own search and critical appraisal of the best evidence to answer specific questions posed: This process is driven by questions rather than by the availability of research evidence. Rather than start with the evidence and summarise what is there, this identifies important clinical questions and then searches for good evidence to answer them. It works like this: when one are faced with the need for new information-it may concern diagnosis, prognosis, or treatment-one uses the following five skills:
- 1) Define a clinical question in a way that allows a clear answer
- 2) Efficiently search for the best studies to answer that question
- 3) Appraise the evidence to determine its strength or credibility
- 4) Determine if it is clinically important
- 5) Decide whether this evidence applies to your patient
When written down, the product of this process is called a critically appraised topic or a CAT. One can see how to do this on the Website for the Centre for Evidence Based Medicine given below.
2. Seeking out evidence-based medical summaries generated by colleagues who are generally aware of the evidence that bears on one's clinical practice and to extract information appropriate to one's individual patients on one's own: Using medical based summaries has long been a common practice, but it suffered from limitations. In the traditional review article, an "expert" states opinions about the proper evaluation and management of a condition; these reviews have been shown, on average, to have low scientific quality. For example, one study showed that experts could not agree, even among themselves, about whether other experts who wrote review articles had a) conducted a competent search for relevant studies, b) generated a bias-free list of citations, c) appropriately judged the scientific quality of the cited articles, or d) appropriately synthesised their conclusions. Another common source of medical summaries has been commercial reviews published by pharmaceutical companies, but these are self-serving by their very nature.
As a result of the evidence based movement, however, enormous effort on many fronts in medicine is now going into finding and summarising research that can reliably inform clinical practice. The international Cochrane Collaboration publishes a rapidly growing and regularly updated library of only the highest quality systematic reviews of group research in health care. The Centre for Reviews and Dissemination in York, England, the Agency for Health Care Policy and Research in Washington DC, and other national bodies are commissioning systematic reviews on important areas of health care. The number of systematic reviews related to interventions in rehabilitation is relatively limited because priority has been given to evaluating treatments for common health problems in the general population. However, the American Academy for Cerebral Palsy and Developmental Medicine has recently undertaken an effort to provide useful and high quality reviews for interventions used in rehabilitation of individuals with developmental disabilities.
3. Accepting and using evidence based practice protocols or standards developed by colleagues: In the United States, the Agency for Health Care Policy and Research in the National Institutes of Health as well as the American Academy for Paediatrics have begun developing evidence based policy practice parameters for some aspects of paediatric health care. The number of these is even more limited, however, than the systematic reviews.
RESOURCES AND TOOLS FOR EVIDENCE BASED HEALTH CARE
Resources for the General Practice of Evidence based health care
Health Information Research Unit at McMaster University (Toronto,Canada): http://www.hiru.mcmaster.ca/ McMaster University is the acknowledged leader in the development of the principles of evidence based health care and the methodological underpinnings of health services research. Much of this has been led by Dr. David Sackett. Sackett and his colleagues (at McMaster and more recently at Oxford where 5 years ago, he became Director of the Centre for Evidence Based Medicine) have spent nearly 20 years researching, teaching, and evaluating strategies that support the practice of evidence based health care. They are responsible for the following, more details of which are available on their Web site:
- Evidence Based Medicine: How to Practice & Teach EBM. This little guidebook in paperback is so clear, well-written, and even entertaining, that one can use it to teach oneself this process. This book, has a extremely thorough section on how to search for evidence-on the Internet, in specialised databases and on Medline.
- Evidence based residency programmes
- Workshops for practising physicians (soon to include nurses)
- User's Guide to the Medical Literature
- Best evidence journals. To facilitate more efficient searching of the medical literature that is often unwieldy and biased, a new type of journal was conceived. A team of librarian/epidemiologists search dozens of clinical journals and, using pre-established subject matter and methodological criteria, select just those studies that are scientifically sound and therefore likely to be valid. These are passed on to a panel of physicians who filter out from those valid articles just the ones they judge to also be clinically important. The first of this type of journal was published in 1991 by the American College of Physicians, American Society of Internal Medicine and was for general internists. In 1995, a joint venture of the American College of Physicians and the British Medical Journal Publications group began publishing Evidence Based Medicine which combines a subset of ACPJC abstracts with those derived from journals in general practice, surgery, obstetrics, paediatrics, and psychiatry. These were followed by Evidence Based Mental Health and Evidence Based Nursing. While these journals also include some evidence based reviews done by collaborative groups, another new one is a compendium of summaries of high quality research evidence, but the contents are driven by questions rather than by the availability of research evidence. This newest journal is called Clinical Evidenc. (BMJ Publishing Group Web site: http://www.bmjpg.com/evid99)
Centre for Evidence Based Medicine (Oxford, UK): www.cebm.jr2.ox.uk/index.extras The teaching and support strategies developed and offered at McMaster have been extended by the group at Oxford as follows:
- Workshops on practising and teaching Evidence based health care
- EBM Toolbox: support for doing critical appraisal of research based on the EBM book
- CATmaker: a programme that helps to write critically appraised topics
- CATbank: database of critically appraised topics
- Evidence Based On Call: practice guidelines tied to critically appraised topics (new project that will become a book)
The website invites interested people to contribute to the EBOC book and/or to the CATbank.
National Library of Medicine, Medline Searching (www.ncbi.nlm.nih.gov/PubMed)
Medline can be searched on the Internet free of cost using a search engine or programme called PubMed. A specialised search feature is available there that is intended to help clinicians detect best evidence through the Medline database. In the PubMed menu, Clinical Queries is to be selected to get built-in search filters that will help to identify only those clinically sound studies of etiology, diagnosis, prognosis and treatment of disorders. This feature uses research methodology that was the result of another of the efforts of the McMaster group to improve the extraction, synthesis and organisation of the research evidence most suited to direct clinical application.
Resources for Practice Guidelines/CATs/Policy Statements
American Academy of Pediatrics (www.aap.org/policy/pcyhome.htm) The Academy has published approximately 300 policy statements, practice guidelines, and model bills although a cursory look through suggests that many are either very general statements or are based on expert opinion. The evidence based topics address the most common childhood diseases (i.e., asthma, otitis media), but there are a few which are relevant to developmental disabilities.
NIH, Agency for Health Care Policy and Research( Washington, DC): www.ahcpr.gov/clinic. Evidence based guidelines represent a new effort of this group which conducts and commissions treatment outcomes research. Six guidelines can be accessed from their Web site; three appear to be relevant to developmental disabilities. Centre for Evidence Based Medicine (Oxford): www.cebm.jr2.ox.uk/index.extras
- Evidence Based On Call project: Practice guidelines tied to critically appraised topics are beginning to appear on this Web site.
- CATbank: database of Critically Appraised Topics
Other CATbanks
- University of Rochester: www.urmc.rochester.edu/smd/Medicine/res/cats
- University of Michigan CATs: www.ped.med.umich.edu/ebm/cat.htm
- University of North Carolina CATs: www.med.unc.edu/medicine/edursrc/catlist.htm
- University of Washington CATs: weber.u.washington.edu/~ebm/topic/index.html
Resources for Systematic Reviews of Evidence
As is true for the secondary journals that filter out the best evidence published in primary journals, for practice guidelines, and for critically appraised topics, priority for evidence based systematic reviews has generally gone to the most common health problems of adults.
Centre for Reviews and Dissemination.(York, UK): www.york.ac.uk Forty six completed reviews carried out or commissioned by the University of York CRD can be accessed in full on their Web site. Two of the 46 topics appear relevant: "A systematic review of the effectiveness of interventions for managing childhood nocturnal enuresis." "Prevention and Treatment of Pressure Sores." 18 additional reviews are reported to be currently in progress.
The Cochrane Collaboration and the Cochrane Library: www.update-software.com
The Cochrane Collaboration is an international non-profit organisation whose aim is to make up to date information about effects of health care readily available world-wide. There are collaborative groups in several countries which take responsibility for building the evidence base for various areas of health care. The Cochrane Library is the collection of the systematic reviews produced by various groups. In addition to the Cochrane Database of Systematic Reviews, the library also contains a Database of Abstracts of strong systematic reviews published elsewhere. There is also a register of Controlled Trials so one can track research in progress, and information on the science of reviewing research. Abstracts of the Cochrane Reviews can be viewed without charge at their Web site, but otherwise the library is available only on a paid subscription basis. Many medical school libraries subscribe to it, but it is also available by individual subscription or on CD-ROM. The reviews are published in an electronic format so that they can be updated as new evidence emerges and mistakes can be corrected in response to appropriate criticisms. The review thereby continues to be in a single place where a distillation of the latest evidence is easily accessible.
Perusal of the groups most likely to produce reviews relevant to issues in developmental disabilities shows that these groups are just getting started. The cystic fibrosis group has produced 7 reviews and are preparing a review on sickle cell and PKU; the epilepsy group has produced 2 reviews; the musculoskeletal group has about 25 reviews in which all but 3 concern adult arthritis; the neuromuscular disease group has 1 review on Guillain-Barre syndrome; the developmental, psychosocial, and learning problems group has produced 4 reviews. There is also a movement disorders group which shows 5 reviews of Parkinson's Disease; however, there is a review of interest to us being prepared on botox for lower limb spasticity in cerebral palsy.
Cochrane Reviews are almost exclusively randomised controlled trials. While use of this gold standard of group research minimises bias, it limits the reviews that will be done to treatments in populations conducive to randomised controlled trials-that is, relatively large and homogeneous populations. Because the populations which comprise developmental disabilities are small in number and very heterogeneous, randomised controlled trials are difficult to conduct and not frequently done.
AACPDM www.aacpdm.org
Evidence based information is not uniform across clinical disciplines but efforts are underway to make them so. One of those efforts is being made by this Academy in the form of systematic reviews of treatment outcomes in developmental disabilities. They chose to start with the evidence and summarise what is there because it was felt that it is important for clinicians to know what types of evidence underlie the various multidisciplinary interventions available-and what kinds of outcomes have been investigated. They expect these evidence tables to identify the gaps in evidence and guide new research to fill those gaps.
A Treatment Outcomes Committee was formed and charged with responsibility for bringing this to fruition. The second task concerned how to synthesise the evidence and the science of appraising it. In other words, they developed a research methodology that will assure meaningful, high quality, and systematic reviews. An electronic format for this Methodology not only makes it readily accessible to everyone, but it will be updated as it is used and improved. Reviews are just beginning to appear on the Website and shorter versions of these reviews will be published in the journal, Developmental Medicine and Child Neurology.
IN CONCLUSION
More and more, clinicians are being exhorted to use the best and most up-to-date evidence when making decisions about patient care. Patients deserve nothing less. No one wants to give (let alone receive) ineffective or harmful treatments, or to fail to use a treatment that has been shown to be substantially better or safer. But finding the best evidence and keeping up to date is a daunting task, especially for generalist clinicians who are expected to know about a broad range of conditions. World-wide, collaborative efforts to develop the databases of information are mushrooming. The fruits of these efforts are increasingly at the fingertips of anyone who has access to the Internet, regardless of where they live and work.
argonauta@foxinternet.net
Title:
ASIA PACIFIC DISABILITY REHABILITATION JOURNAL Vol. 11 @ No. 1 @ 2000
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