Evidence Based Medicine Part I

Centre for Evidence-Based Medicine What I’ve done / do/don’t do l Done: I’ve gotten out of date and retrained in Internal Medicine twice l Do: I run an in-patient General Medicine service (all comers) at a UK DGH: »208 admissions last month »strive to use evidence at the bedside l Don’t: I’ve cancelled my journal subscriptions (and give away the JCI and BMJ)

Centre for Evidence-Based Medicine The Problems: l We need evidence (about the accuracy of diagnostic tests, the power of prognostic markers, the comparative efficacy and safety of interventions, etc.) about 5 times for every in-patient (and twice for every 3 out-patients). l We get less than a third of it

Centre for Evidence-Based Medicine The Problems: l To keep up to date in Internal Medicine, I need to read 17 articles a day, 365 days a year l Need to read l Don’t l Nor does anyone else

Centre for Evidence-Based Medicine Median minutes/week spent reading about my patients: Self-reports at 17 Grand Rounds: l Medical Students: 90 minutes l House Officers (PGY1): 0 (up to 70%=none) l SHOs (PGY2-4):20 (up to 15%=none) l Registrars:45 (up to 40%=none) l Sr. Registrars 30 (up to 15%=none) l Consultants: »Grad. Post 1975:45 (up to 30%=none) »Grad. Pre 1975:30 (up to 40%=none)

Centre for Evidence-Based Medicine Performance deteriorates, too Determinants of the clinical decision to treat some, but not other, hypertensives: 1 Level of blood pressure. 2 Patient’s age. 3 The physician’s year of graduation from medical school. 4 The amount of target-organ damage.

Centre for Evidence-Based Medicine No wonder, then, that CME is growing l Big, and getting huge. l Usually instructionally (fact) oriented. l Several randomised trials have shown that it does not improve clinical performance.

Centre for Evidence-Based Medicine Three solutions Clinical performance can keep up to date: 1 by learning how to practice evidence- based medicine ourselves. 2 by seeking and applying evidence- based medical summaries generated by others. 3 by applying evidence-based strategies for changing our clinical behaviour.

Centre for Evidence-Based Medicine When did EBM begin ? l Certainly in post-revolutionary Paris. l Arguably in B.C China. l Some late-comers named it in 1992.

Centre for Evidence-Based Medicine What evidence-based medicine is: The practice of EBM is the integration of l individual clinical expertise with the l best available external clinical evidence from systematic research. and l patient’s values and expectations

Centre for Evidence-Based Medicine I.Individual Clinical Expertise: l Clinical skills and clinical judgement l Vital for determining whether the evidence (or guideline) applies to the individual patient at all and, if so, how

Centre for Evidence-Based Medicine II. Best External Evidence: l From real clinical research among intact patients. l Has a short doubling-time (10 years). l Replaces currently accepted diagnostic tests and treatments with new ones that are more powerful, more accurate, more efficacious, and safer.

Centre for Evidence-Based Medicine III. Patients’ Values & Expectations l Have always played a central role in determining whether and which interventions take place l We’re getting better at quantifying and integrating them

Centre for Evidence-Based Medicine What EBM is not: l EBM is not cook-book medicine »evidence needs extrapolation to my patient’s unique biology and values l EBM is not cost-cutting medicine »when efficacy for my patient is paramount, costs may rise, not fall

Centre for Evidence-Based Medicine Evidence-Based Medicine: The Practice When caring for patients creates the need for information: 1 Translation to an answerable question (patient/manoeuvre/outcome). 2 Efficient track-down of the best evidence »secondary (pre-appraised) sources e.g., Cochrane; E-B Journals »primary literature

Centre for Evidence-Based Medicine Evidence-Based Medicine: The Practice 3 Critical appraisal of the evidence for its validity and clinical applicability è generation of a 1-page summary. 4 Integration of that critical appraisal with clinical expertise and the patient’s unique biology and beliefs è action. 5 Evaluation of one’s performance.

Centre for Evidence-Based Medicine We needn’t always carry out all 5 steps to provide E-B Care m Asking an answerable question. è Searching è Searching for the best evidence. appraising è Critically-appraising the evidence. m Integrating the evidence with our expertise and our patient’s unique biology and values m evaluating our performance

Centre for Evidence-Based Medicine We’ve identified 3 different modes of practice è “Searching & appraising” »provides E-B care, but is expensive in time and resources è “Searching only” »much, quicker, and if carried out among E- B resources, can provide E-B care è “Replicating” the practice of experts »quickest, but may not distinguish evidence- based from ego-based recommendations

Centre for Evidence-Based Medicine Even fully EB-trained clinicians work in all 3 modes è “Searching & appraising” mode for the problems I encounter daily. è “Searching only” mode among E-B resources for problems I encounter once a month. è “Replicating” the practice of experts mode for problems I encounter once a decade(and crossing my fingers!).

Centre for Evidence-Based Medicine Patients can benefit l Even if <10% of clinicians are capable of practicing in the “searching & appraising” mode (5% of GPs) l As long as most of them practice in a “searching” mode within high-quality evidence sources (70-80% of GPs): »Cochrane Library, E-B Journals, E-B Guidelines, etc

Centre for Evidence-Based Medicine Three solutions Clinical performance can keep up to date: 1 by learning how to practice evidence- based medicine ourselves. 2 by seeking and applying evidence- based medical summaries generated by others. 3 by applying evidence-based strategies for changing our clinical behaviour.

Centre for Evidence-Based Medicine Information required within seconds Systematic reviews, periodically updated, of randomised trials of the effects of health care (from all sources, and in all languages): The Cochrane Collaboration.

Cochrane Systematic Reviews (522; another 500 in preparation) Database of Abstracts of Reviews of Effectiveness (1895) Registry of Randomised Controlled Trials (218,355)

Centre for Evidence-Based Medicine Information required within seconds CD-Evidence-based journals of 2º publication: Ê screen clinical journals per week for clinical articles that pass critical appraisal quality filters è conclusions likely to be true. Ë select the subset that are clinically relevant. Ì summarise as “more-informative” abstracts. Í add commentaries from clinical experts. Î introduce with declarative titles.

Centre for Evidence-Based Medicine

2. Seeking and Applying EBM generated by others Evidence-Based Medicine is published in: l English l French l German l Italian l Portuguese l Spanish

Centre for Evidence-Based Medicine 2. Seeking and Applying EBM generated by others New Evidence-based journals of 2º publication: l E-B Cardiovascular Medicine l E-B Health Policy & Management l E-B Nursing l E-B Mental Health And as new departments in 1º journals.

Centre for Evidence-Based Medicine 2. Seeking and Applying EBM generated by others E-B Textbooks: è E-B Pain Relief è E-B Cardiology èincludes icons for levels of evidence è “E-B On-Call” èincludes > 1300 CATs

Centre for Evidence-Based Medicine Can you really practice EBM? l Is there any “E” for EBM ?

Centre for Evidence-Based Medicine Conventional Wisdom l “only about 15% of medical interventions are supported by solid scientific evidence” (BMJ Editorial)

Centre for Evidence-Based Medicine Even on the U.S. Talk-Shows: (“Health Outrage of the Week”) l “..... this would put 80 to 90 per cent of accepted medical procedures in this country under the heading of quackery!”

Centre for Evidence-Based Medicine Problems with Conventional Wisdom l uses clinical manoeuvres, rather than patients, as the denominator. l tends to focus on high-technology, “big ticket” items. l relies on simple literature searches that miss over half of the most rigorous types of evaluations. l conducted from armchairs.

Centre for Evidence-Based Medicine Performed an empirical study on a busy in-patient service l on the general medicine in-patient service of the Nuffield Department of Medicine at the Oxford-Radcliffe NHS Hospital Trust (“The John Radcliffe”) l all our admissions arise from urgent referral from local GPs or via the Emergency Room