01.intro-ss.new.pdf

SS/EBM/IKA-UDIP-2010

(”Bringing research evidence

into practice”)

Evidence-Based Medicine

Sudigdo Sastroasmoro

Clinical Epidemiology and Evidence-based Medicine Unit

FMUI – CMH, Jakarta


Evidence-based Medicine

• Medicine-based evidence

• Pragmatic research

• Outcome research

Related with

morbidity, mortality, quality of life


Value = Quality

Cost

Morbidity

Mortality

QoL

Patient

Satisfaction

Health

Status


Diagnosis

• Patient with complaint

• History

• Physical

• Simple test

• Specific test: If the test (+) what is the probability that the patient has the disease?

Yes or no answer

Predictive value is the most important

The spectrum of the presentations must resemble that in practice


Treatment

• Patient with certain diagnosis: best treatment?

• Is drug X more effective than Y?

• Focus on the clinical outcome, rather than its explanation (biomolecular markers, etc)

Yes or no outcome most useful

• Not in studies with “idealized” subjects Px with DM are frequently have

hypercholesterolemia, obese, hypertension, etc


Prognosis

• Usually in cohort studies

• To inform about the fate of the patient

• Absolute risk is more important than relative risk

Absolute: Your risk of having second stroke in 1 year is 30%

Relative: Your risk of having second stroke in 1 year is 2 times than in non-smokers (RR = 2)


Pros : “New paradigm in medicine” “Extraordinary innovations, only 2nd to Human Genome Project”

Cons : New version of an old song „Fair‟ : Nothing wrong with EBM, but:

• Be careful in searching evidence • Meta-analyses, clinical trials, and all

study results should be critically appraised

Keyword for EBM: Methodological skill to judge the validity

of study reports (Re. Andersen B: Methodo-logical errors in medical research, 1989)


• Fletcher & Fletcher: CE = The application of epidemiologic principles in problems

encountered in clinical medicine • Sackett et al: CE = The basic science for clinical

medicine • Much resistance by experts • EBM: In principle – no one disagree • All major medical journals have adopted EBM • Centers for EBM all over the world

EBM & Clinical Epidemiology


Previous practice:

6 yrs medical education

40-50 yrs medical practice

Problems with patients: Dx, Rx, Px

Consultants, colleagues Textbooks Handbooks

Lecture notes Clinical guidelines CME, seminars, etc

Journals

Usu. see only Results section, or even worse, Abstract

section


• Trust me

• In my experience ….

• Logically

• Textbook, handbook, capita selecta


The results….

“Opinion-based medicine” • Steroid inj. in prematures to prevent RDS • Routine episiotomy • Routine circumcision • Antibiotics for flu-like syndrome • Use of immunomodulators • “Skin test” before antibiotic injection • Routine chest X-ray for pre-op preparation • CT scan after minor head trauma • etc ……


What is Evidence-based Medicine?

• “The conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients”

• “Pemanfaatan bukti mutakhir yang sahih dalam tata laksana pasien”

• Integration of (1) physician’s competence (2) valid evidence from studies (3) patient’s preference


WHY EBM?

1 Information overload

2 Keeping current with literature

3 Our clinical performance deteriorates with time (“the slippery slope”)

4 Traditional CME does not improve clinical

performance

5 EBM encourages self directed learning process which should overcome the above shortages


Years after graduation

2 4 6 8 10 12

$

100%

THE SLIPPERY SLOPE


Our textbooks are out-of-date

• Fail to recommend Rx up to ten years after it’s been shown to be efficacious.

• Continue to recommend therapy up to ten years after it’s been shown to be useless.


1. Formulate clinical problems in answerable questions

2. Search the best evidence: use internet or other on-

line database for current evidence

3. Critically appraise the evidence for

Validity (was the study valid?)

Importance (were the results clinically important?)

Applicability (could we apply to our patient?)

4. Apply the evidence to patient

5. Evaluate our performance

Steps in EBM practice

VIA


Diagnosis

(Determination of disease or problem)

Treatment

(Intervention necessary to help the patient)

Prognosis

(Prediction of the outcome of the disease)

Main area


(I) Formulating clinical questions


• A 2-year old boy presented with 6-day high fever, conjunctival injection without secretion, skin rash> blood test shows leukocytosis, high ESR, CRP +++. He was suspected to have Kawasaki disease. The pediatrician is aware of the use of immunoglobulin to prevent coronary involvement, but uncertain about the dosage or recent developments.


Medical students: (Background question)

• What is Kawasaki disease? • What is the etiology? • How it is diagnosed? • What is the treatment of choice? • Complications?


House officers (Foreground question)

• In a child with KD, would immunoglobulin treatment, compared with no immunoglobulin, reduce the chance to develop coronary complication?


Foreground

questions

Background

questions

Experience with condition


Other examples

• In women with history of eclampsia, would administration of low-dose aspirin during pregnancy prevent eclampsia? (Prevention)

In young women with solitary thyroid nodule, can USG, compared with biopsy, differentiate between benign from malignant? (Diagnosis)

In women systemic lupus erythematosus, is history of congestive heart failure, compared with no heart failure, worsen the prognosis? (Prognosis)


Four elements of good clinical question: PICO

• The Patient or Problem

• The Intervention / Index

• Comparative intervention (if relevant)

• The Outcome


Four elements of a well constructed clinical question: PICO

P I C O

The main

intervention

considered

The

alternative

to compare

with the

intervention

Outcome

expected

from this

intervention?

Description

of patient

or problem

B e b r i e f a n d s p e c i f i c

mailto:[email protected]

http://www.epi.bris.ac.uk/undergrad/compcrit.htm


Do all clinical questions contain 4 elements of PICO?

• No

• The C implies in the question - PIO

– Does temulawak increase appetite in undernourished children?

• Asking prevalence – PO

– How many percent of patients with TIA who subsequently develop stroke?


Relevance: Type of Evidence

• POE: Patient-oriented evidence

– mortality, morbidity, quality of life

• DOE: Disease-oriented evidence

– pathophysiology, pharmacology, etiology


POEM

• Patient-Oriented

• Evidence


Comparing DOES and POEMs

Prostate

screening

PSA screening

detects prostate

Ca. early

? whether PSA

screening

mortality

DOE exists, but

POEM unknown

Antiarrhythmic

Therapy

Antihypertens.

Therapy

Drug A PVC

On ECG

Drug X BP

Drug X

mortality

Drug A >

mortality

DOE & POEM

contradicts

POEM agrees

With DOE

Example

DOE

POEM

Comment


II

Searching the evidence


III

Appraising the evidence: VIA


Validity: In Methods section:

– design, sample, sample size, eligibility criteria (inclusion, exclusion), sampling method, randomization method, intervention, measurements, methods of analysis, etc

Importance: In Results section

– characteristics of subjects, drop out, analysis, p value, confidence intervals, etc

Applicability: In Discussion section + our patient’s characteristics, local setting

VIA


• Were the subjects randomized?

• Were all subjects received similar treatment?

• Were all relevant outcomes considered?

• Were all subjects randomized included in the analysis?

• Calculate CER, EER, RRR, ARR, and NNT

• Were study subjects similar to our patients in terms of prognostic factors?

Example: Critical appraisal for therapy


Hierarchy of evidence

Meta-analysis of RCT Large RCT Small RCT Non-Randomized trials Observational studies Case series / reports Anecdotes, expert, consensus

Level 1

Level 2

Level 3

Level 4

A

B

C

Rec Weight of

Scientific

Scrutiny

For complete description see www.cebm.net


Implementation of EBM practice: How to get started

1. Teaching EBM in medical schools / PPDS

Easier than to change the already existing attitude

Most important

May be included in formal curricula or integrated in

existing activities: ward rounds, on calls, case

presentations, group discussions, journal clubs, etc

2. Workshop for teaching staff

3. Workshop for practitioners, incl. nurses


Resistance to EBM teaching & learning

Rudimentary skill in critical appraisal /

methodological skill

Limited resources, esp. time factor

Lack of high quality evidence

Skepticism toward evidence-based practice

‘Happy’ with current practice



The

EBM

Cycle

Patient

With problem

Formulate In answerable

question

Search the

evidence

Appraise The

evidence

Apply The

evidence


Criticism to EBM • EBM makes expensive medical care

• EBM cannot be implemented in developing countries

• EBM is costly and time consuming

• EBM ignore pathophysiology & reasoning

• EBM ignore experience and clinical judgment

• EB-guidelines etc interfere with professional autonomy


Criticism to EBM

EBM makes expensive medical care

Cf:

–Routine antibiotics for ARTI & diarrhea

–Liberal indication for C-section

–Unnecessary sophisticated procedures / exams

–Unnecessary / harmful treatment: steroid for recurrent cough


Criticism to EBM

EBM cannot be implemented in developing countries

– By definition EBM is implemented if it is implementable (patient’s preference and local condition) – for the benefit of the patients and the community


Criticism to EBM

EBM is costly and time consuming

– EBM does requires facilities at the cost of quality medical care!

– Cost benefit ratio should be assessed in individual and community levels


Criticism to EBM

EBM ignores pathophysiology & reasoning

– EBM encourages clinical reasoning in the light of valid and important evidence

– Pathophysiology and reasoning should be seen as hypothesis and should end-up in empirical evidence


Criticism to EBM

EBM ignore experience and clinical judgment

– Personal experience and clinical judgment are by no means can be eliminated

– EBM encourage detailed and systematic documentation of experience and judgment

– Subjective experience should be, whenever possible, translated into more objective measures


Criticism to EBM EB-guidelines interfere with professional autonomy

– Professional conduct (competence, altruism, openness, collegiality, ethics) is encouraged in EBM

– Every physician should develop their own practice attitude based on his/her profess-ionalism, valid evidence, and patient’s values

– Development of clinical guidelines and other standards of care should be seen as a guide and implemented according to clinical setting


Advantages of EBM • Encourages reading habit • Improves methodological skill (and

willingness to do research?!) • Encourages rational & up to date

management of patients • Reduces intuition & judgment in clinical

practice, but not eliminates them • Consistent with ethical and medico-legal

aspects of patient management


End result

Self directed, life-long learning attitude

for high quality patient care


Conclusion

EBM is nothing more than a framework of systematic use of current valid study results relevant to our patient

01.intro-ss.new.pdf

Documents

practice ssebmikaudip

jakarta ssebmikaudip

quality of life ssebmikaudip

abstract section ssebmikaudip

research evidence

capita selecta ssebmikaudip

valid evidence

clinical outcome