evidence based medicine part i

Evidence Based Medicine

www.bradfordvts.co.

uk

Part I

Centre for Evidence-Based Medicine

What I’ve done / do/don’t do

Done: I’ve gotten out of date and retrained in Internal Medicine twice

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

Don’t: I’ve cancelled my journal subscriptions (and give away the JCI and BMJ)

Centre for Evidence-Based Medicine

The Problems:

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).

We get less than a third of it

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The Problems:

To keep up to date in Internal Medicine, I need to read 17 articles a day, 365 days a year

Need to read Don’t Nor does anyone else

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Median minutes/week spent reading about my

patients:

Self-reports at 17 Grand Rounds: Medical Students: 90 minutes House Officers (PGY1): 0 (up to 70%=none) SHOs (PGY2-4): 20 (up to 15%=none) Registrars: 45 (up to 40%=none) Sr. Registrars 30 (up to 15%=none) 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.

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No wonder, then, that CME is growing

Big, and getting huge. Usually instructionally (fact) oriented. 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 ?

Certainly in post-revolutionary Paris.

Arguably in B.C China.

Some late-comers named it in 1992.

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What evidence-based medicine is:

The practice of EBM is the integration of individual clinical expertise

with the best available external clinical evidence

from systematic research.and

patient’s values and expectations

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I.Individual Clinical Expertise:

Clinical skills and clinical judgement Vital for determining whether the

evidence (or guideline) applies to the individual patient at all and, if so, how

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II. Best External Evidence:

From real clinical research amongintact patients.

Has a short doubling-time (10 years). Replaces currently accepted diagnostic

tests and treatments with new ones that are more powerful, more accurate, more efficacious, and safer.

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III. Patients’ Values & Expectations

Have always played a central role in determining whether and which interventions take place

We’re getting better at quantifying and integrating them

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What EBM is not:

EBM is not cook-book medicine» evidence needs extrapolation to my

patient’s unique biology and values EBM is not cost-cutting medicine

» when efficacy for my patient is paramount, costs may rise, not fall

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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

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Evidence-Based Medicine:The Practice

3 Critical appraisal of the evidence for its validity and clinical applicability generation of a 1-page summary.

4 Integration of that critical appraisal with clinical expertise and the patient’s unique biology and beliefs action.

5 Evaluation of one’s performance.

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We needn’t always carry out all 5 steps to provide

E-B Care

Asking an answerable question. SearchingSearching for the best evidence. Critically-appraisingappraising the evidence. Integrating the evidence with our

expertise and our patient’s unique biology and values

evaluating our performance

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We’ve identified 3 different modes of practice

“Searching & appraising”» provides E-B care, but is expensive in time and

resources “Searching only”

» much, quicker, and if carried out among E-B resources, can provide E-B care

“Replicating” the practice of experts» quickest, but may not distinguish evidence-

based from ego-based recommendations

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Even fully EB-trained clinicians work in all 3

modes

“Searching & appraising” mode for the problems I encounter daily.

“Searching only” mode among E-B resources for problems I encounter once a month.

“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

Even if <10% of clinicians are capable of practicing in the “searching & appraising” mode (5% of GPs)

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)

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Information required within seconds

CD-Evidence-based journals of 2º publication:

screen 50-70 clinical journals per week for clinical articles that pass critical appraisal quality filters conclusions likely to be true.

select the subset that are clinically relevant.

summarise as “more-informative” abstracts.

add commentaries from clinical experts.

introduce with declarative titles.

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2. Seeking and Applying EBM generated by others

Evidence-Based Medicine is published in: English French German Italian Portuguese Spanish

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2. Seeking and Applying EBM generated by others

New Evidence-based journals of 2º publication: E-B Cardiovascular Medicine E-B Health Policy & Management E-B Nursing E-B Mental Health

And as new departments in 1º journals.

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2. Seeking and Applying EBM generated by others

E-B Textbooks: E-B Pain Relief E-B Cardiology

includes icons for levels of evidence “E-B On-Call”

includes > 1300 CATs

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Can you really practice EBM?

Is there any “E” for EBM ?

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Conventional Wisdom

“only about 15% of medical interventions are supported by solid scientific evidence” (BMJ Editorial)

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Even on the U.S. Talk-Shows: (“Health Outrage of

the Week”)

“..... this would put 80 to 90 per cent of accepted medical procedures in this country under the heading of quackery!”

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Problems with Conventional Wisdom

uses clinical manoeuvres, rather than patients, as the denominator.

tends to focus on high-technology, “big ticket” items.

relies on simple literature searches that miss over half of the most rigorous types of evaluations.

conducted from armchairs.

Centre for Evidence-Based Medicine

Performed an empirical study on a busy in-patient

service

on the general medicine in-patient service of the Nuffield Department of Medicine at the Oxford-Radcliffe NHS Hospital Trust (“The John Radcliffe”)

all our admissions arise from urgent referral from local GPs or via the Emergency Room