Pre-reading for hands-on EBM session for MCGP
What is EBM?
Evidence-based medicine (EBM) is the integration of best research evidence with clinical expertise and patient values.
- by best research evidence we mean clinically relevant research, often from the basic sciences of medicine, but especially from patient centered clinical research into treatment, diagnosis, aetiology etc.
- by clinical expertise we mean the ability to use our clinical skills and past experience to rapidly identify each patient’s unique health state and diagnosis, their individual risks and benefits of potential interventions, and their personal values and expectations.
- by patient values we mean the unique preferences, concerns and expectations each patient brings to a clinical encounter and which must be integrated into clinical decisions if they are to serve the patient.
Good doctors use both individual clinical expertise and the best available external evidence, and neither alone is enough. Without clinical expertise, practice risks becoming tyrannised by evidence, for even excellent external evidence may be inapplicable to or inappropriate for an individual patient. Without current best evidence, practice risks becoming rapidly out of date, to the detriment of patients.
Evidence based medicine: what isn’t it
Evidence based medicine is neither old hat nor impossible to practice. The argument that “everyone already is doing it” falls before evidence of striking variations in both the integration of patient values into our clinical behaviour and in the rates with which clinicians provide interventions to their patients.
Evidence based medicine is not “cookbook” medicine. Because it requires a bottom up approach that integrates the best external evidence with individual clinical expertise and patients’ choice, it cannot result in slavish, cookbook approaches to individual patient care. External clinical evidence can inform, but can never replace, individual clinical expertise, and it is this expertise that decides whether the external evidence applies to the individual patient at all and, if so, how it should be integrated into a clinical decision.
Evidence based medicine is not restricted to randomised trials and meta-analyses. It involves tracking down the best external evidence with which to answer our clinical questions. To find out about the accuracy of a diagnostic test, we need to find proper cross sectional studies of patients clinically suspected of harbouring the relevant disorder, not a randomised trial. For a question about prognosis, we need proper follow up studies of patients assembled at a uniform, early point in the clinical course of their disease. And sometimes the evidence we need will come from the basic sciences such as genetics or immunology. It is when asking questions about therapy that we should try to avoid the non-experimental approaches, since these routinely lead to false positive conclusions about efficacy. Because the randomised trial, and especially the systematic review of several randomised trials, is so much more likely to inform us and so much less likely to mislead us, it has become the “gold standard” for judging whether a treatment does more good than harm. However, some questions about therapy do not require randomised trials (successful interventions for otherwise fatal conditions) or cannot wait for the trials to be conducted. And if no randomised trial has been carried out for our patient’s predicament, we must follow the trail to the next best external evidence and work from there. (BMJ Editorial 1996;312:71-72)
How to we practice EBM?
|Orthodox EBM (Traditional)||New school EBM|
|1.Formulate an answerable question
3. Appraise articles
4. Apply to patient
|1. Formulate an answerable question
2 & 3. Search pre-appraised evidence (point of care evidence resources)
4. Apply to patient
The first step of either school of EBM is ‘Formulating an answerable question’ using the PICO(T) format.
This is the important first step to get it correct before you start searching. Please take a few minutes for an introduction to basics of study design – Centre of Evidence Based Medicine, Oxford University
Apart from asking answerable questions and applying clinical expertise, the old-school steps are no longer as necessary for physicians who practice EBM today, because of the evolution of evidence-based information services. New-school EBM is using information resources that have EBM processes and principles built into them. These are also called POCR/PAER.
New-school EBM vastly reduces the burden of primary evidence critical appraisal, but one key appraisal task cannot be neglected by the user: assessing the truth of an information resource’s claim that it is evidence based. (Evidence at Point Of Care – BMJ Best Practice)
The new tools of Point of Care Resources (POCR) makes it possible for the busy clinicians to obtain the best evidence even during consultations. POCR can be defined as Web-based medical compendia specifically designed to deliver pre-digested, rapidly accessible, comprehensive, periodically updated, and evidence-based information (and possibly also guidance) to clinicians. The issue for clinicians are which of the so-called POCR tools are reliable.
In 2011-12 several independent reviews compared several POCR in different aspects: editorial quality, authorship, literature search, review process and speed of updating. The POCR that came on top are DynaMed, UpToDate and Best Practice.
Pre-appraised evidence / Point of Care evidence (POCR) resources
|Cochrane Library – Link||Free access. Includes Cochrane Database of Systematic Reviews|
|DynaMed Plus – Link||One stop point of care resource for generalists.|
|UpToDate – Link||Probably the best medical textbook for clinicians|
|BMJ Best Practice – Link||One stop point of care resource for generalist.|
|Evidence Based Medicine Journal – Link||One of the best secondary journals for generalist to keep up to date.
|Essential Evidence Plus – Link|
PubMed is the US government interface to MEDLINE. This is free to anybody with an internet connection. PubMed comprises more than 29 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
PubMed = MEDLINE (over 25 million citations) + others (journals, online books etc)
MEDLINE is the U.S. National Library of Medicine® (NLM) premier bibliographic database that contains more than 25 million references to journal articles in life sciences with a concentration on biomedicine. A distinctive feature of MEDLINE is that the records are indexed with NLM Medical Subject Headings (MeSH®). MEDLINE is the online counterpart to MEDLARS® (MEDical Literature Analysis and Retrieval System) that originated in 1964.
Currently, citations from more than 5,200 worldwide journals in about 40 languages; about 60 languages for older journals. MEDLINE is the primary component of PubMed. Between 2,000-4,000 completed references are added to MEDLINE each day Tuesday through Saturday; over 712,000 total added in 2009. For citations added in 2008: about 47% are for cited articles published in the U.S., about 92% are published in English, and about 82% have English abstracts written by authors of the articles. A growing number of MEDLINE citations contain a link to the free full text of the article archived in PubMed Central® or to other sites.
MedlinePlus another service offered by the NLM, provides patient/consumer-oriented health information.
Please take a few minutes to do these on-line tutorials
|How do I search PubMed?|
Primary bibliographic databases
|MEDLINE||First biomedical bibliographic database over 29 million articles|
With over 20 million records from more than 7,000 active Journals. 1,800 biomedical titles not offered by Medline. Covers in-depth of pharmaceutical journals. European equivalent of Medline.
Systematic coverage of the psychological literature from the year 1800s to the present
|CINAHL||Cumulative Index to Nursing and Allied Health Literature, is the most comprehensive resource for nursing and allied health literature.|
The Cochrane Library is a collection of six databases that contain different types of high-quality, independent evidence to inform healthcare decision-making.
The CDSR includes all Cochrane Reviews (and protocols) prepared by Cochrane Review Groups in the Cochrane Collaboration. Each Cochrane Review is a peer-reviewed systematic review that has been prepared and supervised by a Cochrane Review Group. The Cochrane library adds and updates about 20,000 resources annually. The majority are for the CCRCT. The CDSR has about 7000 systematic reviews in total. It also contains systematic reviews from non-Cochrane sources in the DARE database.
Secondary Journals & Websites
Secondary Journals are journals that summarise other journals – e.g. EBM journal
Communicating the evidence to your patient
When you have the best research evidence for the condition that you have diagnosed using your clinical expertise, you have to consider what the patient wants and the circumstances and context of your practice. One of the most difficult things is to convey the evidence you obtain in a simple understandable way to the patient in front of you. The two papers below will give you information as to how to communicate the risks especially related to treatment questions.
After asking an answerable structured question, accessing the evidence and appraising it, the next step is to communicate the evidence to the patient. To most people, the word risk means “danger”: for example, “lion taming is a high-risk hobby.” But risk is also used to mean the chance that something will happen to you: for example, “in this group of patients, the risk of heart attack is about 10 per cent ”. In EBM we use risk as a synonym for chance. Usually, we’ll be talking about the chance of something bad happening (like having a heart attack). Strictly speaking, risk can refer to the chance of anything—good or bad—happening
Explaining risks: turning numerical data into meaningful Pictures. Adrian Edwards, Glyn Elwyn, Al Mulley. BMJ 2002;324:827–30 and
Helping Patients Decide: Ten Steps to Better Risk Communication Angela Fagerlin, Brian J. Zikmund-Fisher, Peter A. Ubel. J Natl Cancer Inst 2011;103:1–8