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Done: I’ve gotten out of date and retrained in Internal Medicine twice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


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


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


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)


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.


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.


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.


When did EBM begin ?

Certainly in post-revolutionary Paris.

Arguably in B.C China.

Some late-comers named it in 1992.


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


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


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.


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


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


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


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.


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


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


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!).


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


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.


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)


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.


2. Seeking and Applying EBM generated by others

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



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.



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

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

includes > 1300 CATs


Can you really practice EBM?

Is there any “E” for EBM ?


Conventional Wisdom

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


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!”


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.


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

evidence based medicine part i

Documents