SS/EBM/IKA-UDIP-2010 (”Bringing research evidence into practice”) Evidence-Based Medicine Sudigdo Sastroasmoro Clinical Epidemiology and Evidence-based.

SS/EBM/IKA-UDIP-2010

(”Bringing research evidenceinto practice”)

Evidence-Based Medicine

Sudigdo Sastroasmoro

Clinical Epidemiology and Evidence-based Medicine Unit

FMUI – CMH, Jakarta


5-day workshop3-day workshop2-day workshop


Evidence-based Medicine

Opinion-based medicineExperience-based medicinePower-based medicineHope-based medicineLogic-based medicineErratic-based medicine

versus


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)


Evidence-based Medicine

Medicine-based evidencePragmatic researchOutcome research

Related with morbidity, mortality, quality

of life


Value = Quality

Cost

MorbidityMortality

QoL

PatientSatisfaction

Health Status


Diagnosis

Patient with complaintHistoryPhysicalSimple testSpecific 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


TreatmentPatient 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 usefulNot in studies with “idealized” subjects Px with DM are frequently have

hypercholesterolemia, obese, hypertension, etc


Prognosis

Usually in cohort studiesTo 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)


Fletcher & Fletcher: CE = The application ofepidemiologic 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


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


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


The results….“Opinion-based medicine”

Steroid inj. in prematures to prevent RDSRoutine episiotomyRoutine circumcisionAntibiotics for flu-like syndromeUse of immunomodulators“Skin test” before antibiotic injectionRoutine chest X-ray for pre-op preparationCT scan after minor head traumaetc ……


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


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)


Y= a + b 1x 1

+ b 2X 2

+ b 3X 3

+ ……. + b ix i

εφlnΣδψ 2

$ 6,000

Yesss!!!



Dean, Harvard Medical School to students:

“We believe that 50% of what we are teaching to you now will prove to be false 5 years later; the problem is that we do not know which 50%”


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 performance

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


Years after graduation

Relative% ofremainingknowledge

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 patient5. 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?


Foregroundquestions

Backgroundquestions

Experience with condition


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

Other examples

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: PICOThe Patient or ProblemThe Intervention / IndexComparative intervention (if relevant)The Outcome


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


Do all clinical questions contain 4 elements of

PICO?NoThe C implies in the question - PIO

Does temulawak increase appetite in undernourished children?

Asking prevalence – POWhat is the prevalence of abnormal gene XYZ in patients with -thalassemia?


Relevance: Type of Evidence

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

DOE: Disease-oriented evidencepathophysiology, pharmacology, etiology


POEM

Patient-OrientedEvidence


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


IISearching the evidence


IIIAppraising 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 sectioncharacteristics 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

RecWeight ofScientific 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


Physician’s competence

Valid evidencePatient’s values


TheEBMCycle

PatientWith problem

FormulateIn answerable

question

Search theevidence

AppraiseThe

evidence

ApplyThe

evidence


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


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


End result

Self directed, life-long learning attitude

for high quality patient care


Conclusion

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

SS/EBM/IKA-UDIP-2010 (”Bringing research evidence into practice”) Evidence-Based Medicine Sudigdo Sastroasmoro Clinical Epidemiology and Evidence-based.

Documents

practice slide

jakarta slide

day workshop slide

research evidence

patients preference

slippery slope slide

current evidence

later evidence