SS/EBM/Intro/2010 E vidence Sudigdo Sastroasmoro ([email protected]) Medical School University of Indonesia (”Bringing research evidence into practice”)

SS/EBM/Intro/2010

E vidence

Sudigdo Sastroasmoro([email protected])

Medical School University of Indonesia

(”Bringing research evidenceinto practice”)

(”Bringing research evidenceinto practice”)

B ased

M edicine

SS/EBM/Intro/2010

Dr. Benjamin Spock:Baby and Child Care

“I think it is preferable to accustom a baby to sleeping on his stomach from the start of he is willing. He may change later when he learns to turn over”.

Later evidence indicates that prone position is aan significant risk factor for SIDS (sudden infant death syndrome)

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Fletcher & Fletcher: CE = The application of

epidemiologic principles in problems encountered in clinical medicineSackett et al: CE = The basic science for clinical medicineMuch resistance by expertsEBM: In principle – no one disagreeAll major medical journals have adopted EBMCenters for EBM all over the world

EBM & Clinical Epidemiology

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Previous practice:

6 yrs medical

education

40-50 yrsmedical practice

Problems with patients:

Dx, Rx, Px

Consultants, colleaguesTextbooksHandbooks

Lecture notesClinical

guidelinesCME, seminars,

etcJournals

Usu. see only Results section,

or even worse, Abstract section

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Trust meIn my experience ….LogicallyTextbook, handbook, capita selecta

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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

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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, etc. should be critically appraised

Keyword for EBM: Methodological skill to judge the validity

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

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(Mark Twain)

“Hierarchy of Lies”

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WHY EBM?1. Information overload 2. Keeping current with literature3. Our clinical performance

deteriorates with time (“the slippery slope”)

4. Traditional CME does not improve clinical

performance5. EBM encourages self directed

learning process which should overcome the above shortages

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>25,000 periodical (journals)6,000,000 articles annually17,000 biomedical books annually3000 recognized diseases1500 therapeutic regimens (+250 annually)

The fact……..

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The Flora and Fauna of the Medical Jungle

Original ResearchAcademic ReviewsDecision/Cost AnalysisMedical Cookbooks (Practice Guidelines)Translation JournalsCMEClinical Experience

ExpertsNewsletters and Survey ServicesPharmaceutical RepresentativesComputer sourcesAudiotapesQualitative Research

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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.

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The inevitable consequence:

On average, the clinically-important knowledge of physicians deteriorates rapidly after we complete our training.

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Years after graduation

Relative% ofremainingknowledge

2 4 6 8 10 12

$100%

THE SLIPPERY SLOPE

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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 patient5. Evaluate our performance

Steps in EBM practice

VIA

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Diagnosis(Determination of disease or problem)

Treatment(Intervention necessary to help the patient)

Prognosis(Prediction of the outcome of the disease)

Main area

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Meta-analysisClinical guidelinesEconomic analysis

Clinical decision makingCost-effectiveness analysis

Qualitative research

Others:

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(I)Formulating clinical

questions

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A 2-month old infant with large VSDBirth weight 3.1 kgWeight 3.8 kg, HR=132, RR 68Retractions (+)Systolic murmur, gallop rhythmHepatomegalyDx: Large VSD, Heart failure, Failure to thriveDefinite Rx: early surgeryAlternative Rx: Drugs first?

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Medical students:(Background question)

What is VSD?How to Dx?What are symptoms & signs of CHF in infants with L-R shunt?What is the treatment?

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House officers(Foreground question)

In infants with large VSD and CHF, would administration of digoxin or other inotropic agent delay the need for surgery?

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Foregroundquestions

Backgroundquestions

Experience with condition

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In neonates born to mothers with history of herpes simplex infection, does the administration of IVIG (intravenous immunoglobulin) reduce the possibility of neonatal herpes?

Other example

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In women with history of eclampsia, would administration of low-dose aspirin (compared with no aspirin) during pregnancy prevent eclampsia?

Other example

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Examples of clinical questions in practice

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Example: Etiology

P I C O

“In premature infants …

…is mode

of delivery

…

…a risk factor for the develop

mnt HMD?

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Example: Diagnosis

P I C O

“In patients

with suspect

edmalaria

…can rapid test

…compare

dwith microsco

peexam

…effectively establish diagnosis?

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Example: Therapy

P I C O

“For px with

StevensJohnson syndro

me

will early

IVImmuno

-globulin

(IVIG)

…when compared

withno IVIG

…prevent severe

complica-tions?

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Example: Prognosis

P I C O

“For px with SLE

…wouldhistory

ofheart failure

…compared with no history of HF

…worsenthe

prognosis?

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Four elements of good clinical

question: PICOThe Patient or ProblemThe InterventionComparative intervention The Outcome

Domain

Determinants

Outcome

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Four elements of a well constructed clinical

question: PICO

P I C O

The maininterventionconsidered

The alternativeto compare

with theintervention

Outcomeexpected from this

intervention?

Descriptionof patient

or problem

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

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Remember (1)Not all clinical questions contain 4 elements, depending on the nature of the condition being asked.

Examples: In post-menopausal women on hormone

replacement therapy, does addition of vitamin X reduce the likelihood of developing hip fracture? (PIO)

In patients with thalassemia HbE disease, what is the prevalence of single gene mutation? (PO)

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Remember (2)In the PICO context, Intervention does not necessarily mean TREATMENT or PREVENTION, but may be: A diagnostic test (for diagnosis)

• In a patient with solitary thyroid nodule, does ultrasound exam, compared with needle biopsy, differentiate malignant from benign tumor?

A risk factor (for etiology, prognosis)• Is poor fiber diet a risk factor for the

development of colo-rectal cancer? A condition in the patient himself (for

prognosis)• In patient with SLE, would the history of

cardiac failure, compared with no failure, worsen the long-term prognosis?

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Relevance: Type of Evidence

POE: Patient-oriented evidence mortality, morbidity, quality of

lifeDOE: Disease-oriented evidence pathophysiology,

pharmacology, etiology

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Comparing DOEs and POEMs

Prostatescreening

PSA screeningdetects prostate

Ca. early

? whether PSAscreening mortality

DOE exists, butPOEM unknown

AntiarrhythmicTherapy

Antihypertens.Therapy

Drug A PVCOn ECG

Drug X BP Drug X mortality

Drug A > mortality

DOE & POEMcontradicts

POEM agreesWith DOE

Example DOE POEM Comment

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IISearching the

evidence

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Examples of on-line Journals / Databases

http://bmj.comhttp://adc/bmjjournals.comMEDLINE/PubMedEMBASEMDConsultAAP Journal ClubCochrane Library

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Note: Spelling (American / British), terminologyFollow rigidly the instructions of each website

Examples:“Host vs graft reaction” AND managementhemosiderosis AND thalassemia OR thalassaemia“breast cancer” OR “Ca mammae” AND immunoglobulin OR IVIG

Use keywords for searching

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IIIAppraising the

evidence:VIA

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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

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Validity - other approach: RAMMbo

Recruitment: sampling methods, eligibility criteria, sample size Allocation: randomization? concealment? Maintenance: many drop outs? Measurement

blinded – RCT, Dx testobjective – validity & reliability

Can be applied for all designs with necessaryAdjustment according to nature of the design

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

Example: Critical appraisal for therapy

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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

RecWeight ofScientific Scrutiny

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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

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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

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Development of EBM practice

Passive diffusion model Active dissemination model Coordinated implementation

model: Patients & community Health administrators Public policy makers Clinical policy makers

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TheEBMCycle

PatientWith problem

FormulateIn answerable

question

Search theevidence

Critically Appraise

The evidence

ApplyThe evidence

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Accessible population

(time, place)

Usu. Based on practicalpurposes

Appropriatesampling technique

[Non-response, drop outs,withdrawals, loss to follow-up]

Target population(Domain)

(demographic, clinical)

IntendedSample

[Subjects selectedfor study]

Actualstudy

subjects

Subjectscompletedthe study

Your patient is here!

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Criticism to EBMEBM makes expensive medical careEBM cannot be implemented in developing countriesEBM is costly and time consumingEBM ignore pathophysiology & reasoningEBM ignore experience and clinical judgmentEB-guidelines etc interfere with professional autonomy

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Criticism to EBM

EBM makes expensive medical care

Cf:Routine antibiotics for ARTI & diarrheaLiberal indication for C-sectionUnnecessary sophisticated procedures / examsUnnecessary / harmful treatment: steroid for recurrent cough

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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

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Criticism to EBM

EBM is costly and time consumingEBM does requires facilities at the cost of quality medical care!Cost benefit ratio should be assessed in individual and community levels

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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

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Criticism to EBMEBM ignore experience and clinical

judgment

Personal experience and clinical judgment are by no means can be eliminatedEBM encourage detailed and systematic documentation of experience and judgmentSubjective experience should be, whenever possible, translated into more objective measures

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Criticism to EBM

EB-guidelines etc interfere with professional

autonomyProfessional conduct (competence, altruism, openness, collegiality, ethics) is encouraged in EBMEvery physician should develop their own practice attitude based on his/her profess-ionalism, valid evidence, and patient’s valuesDevelopment of clinical guidelines and other standards of care should be seen as a guide and implemented according to clinical setting

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Barriers to the implementation of

Evidence-Based Medicine

“It takes too long.”

“Possibly a limitation

to my clinical

freedom.”“It questions my

professional

autonomy.”

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Advantages of EBMEncourages reading habitImproves methodological skill (and willingness to do research?!)Encourages rational & up to date management of patientsReduces intuition & judgment in clinical practice, but not eliminates themConsistent with ethical and medico-legal aspects of patient management

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End result

Self directed, life-long learning attitude

for high quality patient care

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Conclusion

EBM is nothing more than aframework of systematic use ofcurrent valid study results relevant to our patient

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Evidence-based CardiologyEvidence-based PediatricsEvidence-based Ob-GynEvidence-based Dentistry Evidence-based Nursing Evidence-based Health PolicyEvidence-based Health Technology AssessmentEvidence-based Decision MakingEvidence-based Health Performance IndicatorsEvidence-based Clinical AuditEvidence-based Risk Management …….Evidence-based Everything!!!

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In God we trustAll others must have

evidence

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Remember, however …...

Medicine is the science of uncertainty

and the art of probabilities