Evidence-Based Medicine

MEDICINE 433C-81

Jane Gagliardi and Megan von Isenburg

The EBM Class

• http://sites.duke.edu/ebmcourse/

• GOAL: – Interactive

– Engaging

– Clinically relevant

• HOW TO RECEIVE THE CLINICAL CREDIT: – Show up on time for all 6 sessions* and

participate!

– Complete (clinically-relevant, not onerous) work

NO iPads, SmartPhones, Internet, Stock-checking, or emailing during the two hour session

The EBM Assignment

• By the end of the course, for one specific case:

– Assess a situation and/or a patient relevant to your clinical practice (past or anticipated)

– Ask a relevant, focused clinical question

– Acquire evidence of the most appropriate type in the literature

– Appraise the evidence using validity criteria

– Apply the results to the situation you have identified

Why are we all here?

A. The Medical Center Library is a happening place

B. I heard there would be pizza

C. It’s the obvious place to be after MedStats

D. That question is way too deep for 6:00 pm on a Thursday

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ay too...

25% 25%25%25%

Why are we all here?

• Healthcare expenditure is higher in the US than in other countries

• Other countries have better health-related outcomes

• Adult patients in the US receive about half the “right care at the right time” (McGlynn et al., 2003).

….no, really…

N Engl J Med 2003; 348:2635-2645

Consider…

• A study of steel mill workers identified by on-the-job screening program with hypertension

– ½ sent to primary care providers for specific treatment of hypertension

– ½ sent to on-the-job-site provider for algorithm-based treatment of hypertension

Adapted from Virginia Moyer, 1/14/2014

Consider…

• A study of steel mill workers identified by on-the-job screening program with hypertension

• Unexpectedly low rates of treatment by primary care providers

Adapted from Virginia Moyer, 1/14/2014

Consider…

• A study of steel mill workers identified by on-the-job screening program with hypertension

• Unexpectedly low rates of treatment by primary care providers

• Factors associated with likelihood of prescription of an antihypertensive agent:

Adapted from Virginia Moyer, 1/14/2014

Consider…

• Factors associated with likelihood of prescription of an antihypertensive agent:

1. Diastolic blood pressure

2. Age

3.

4. Target end-organ damage

Adapted from Virginia Moyer, 1/14/2014

Consider…

• Factors associated with likelihood of prescription of an antihypertensive agent:

1. Diastolic blood pressure

2. Age

3. Time since graduation from medical school

4. Target end-organ damage

Adapted from Virginia Moyer, 1/14/2014

The Dartmouth Atlas

– 2-decade / ongoing study

– Significant geographical variations in practice

• Not attributable to any particular health-related issue

(http://www.dartmouthatlas.org/)

The Dartmouth Atlas

Using the Best Available Evidence?

Which of the following single sample study type IS the best available evidence to answer a question about THERAPY?

A. Case Series

B. Cohort Study

C. Case Control

D. Randomized Controlled Trial

E. Cross-Sectional Study

Case Serie

s

Cohort Stu

dy

Case C

ontrol

Randomize

d Contro

lled T

rial

Cross

-Sect

ional S

tudy

20% 20% 20%20%20%

Using the Best Available Evidence?

• Studies from multiple disciplines… – Internal Medicine

– Family Medicine

– Psychiatry

– Surgery

– Anaesthesia

– Pediatrics

• …show that 11-65% of treatment choices are supported by findings from Randomized Controlled Trials

Why Not Use the Evidence?

Will YOU Use the Evidence?

What type of practice do you envision working in when you grow up?

A. Large Group Practice (includes Academic, VA, large private practice (> 10 physicians)

B. Small Group Practice or Solo Practice

Larg

e Gro

up Pra

ctice

(in...

Small

Gro

up Pra

ctice

or .

..

50%50%

Will YOU Use the Evidence?

Tell the Truth, Now… When I started medical school, I thought:

A. “There is a right answer to every clinical dilemma, and I will learn algorithms to find it.”

B. “There is no right answer; doctors use their best clinical judgment and hope things turn out OK.”

C. “There is a right answer; I will learn how to seek the most up-to-date evidence to find it.”

D. There is no right answer; we live in a world of uncertainty, but doctors do the best they can to find the most up-to-date evidence for a situation.”

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.

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25% 25%25%25%

How Doctors Make Decisions

Traditional Decision-Making

• Biological Plausibility

• Clinical Reasoning

• Personal Experience

Evidence-Based Medicine

• Best available evidence in human studies…

• Integrated with clinical expertise…

• Recognizing patient values… • Recognizing a hierarchy of

evidence…

Evidence-Based Medicine

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

• Evidence-based medicine is not restricted to randomised trials and meta-analyses

http://www.cebm.net/?o=1014

Without current best evidence, practice risks

becoming rapidly out of date, to the detriment of patients

It involves tracking down the best external evidence

with which to answer our clinical questions.

Incorporating EBM into Daily Practice

EBM as a CLINICAL TOOL

ASSESS

ASK

ACQUIRE

APPRAISE

APPLY

The 5 A’s

EBM Cycle

MUST CONSIDER: - Patient preference - Access to care - Quality of life - Goals of care

WHAT’S GOING ON? - History and Physical - Initial Formulation

PICOTT - Patient / Population - Intervention - Control - Outcome - Type of Question - Type of Study

LITERATURE SEARCH

VALIDITY CRITERIA - Methods - Results - Sources of Bias - Strength of evidence

HIERARCHY of EVIDENCE

(This can’t possibly be the first HIERARCHY you have encountered at Duke…or is it???)

HIERARCHY of EVIDENCE

WHY a HIERARCHY?

STUDY DESIGN

• Case report

• Case series

• Case-control study

• Cohort study

• Randomized controlled trial

• Systematic review

STUDY DESIGN

TEST YOUR KNOWLEDGE!

In a study of risk factors for the development of autism, investigators enrolled consecutive children during their first newborn well child check. Each child’s caretaker was asked whether or not the house was near power lines. The children were followed for 5 years and the frequency of autism in children with and without proximity to power lines was assessed.

A. Randomized controlled trial (RCT)

B. Prospective cohort

C. Retrospective cohort

D. Case-control

E. Case series Random

ized co

ntrolle

d tr...

Prosp

ectiv

e cohort

Retrosp

ectiv

e cohort

Case-co

ntrol

Case se

ries

20% 20% 20%20%20%

In a study of risk factors for the development of autism, investigators accessed records from MAESTRO Care. . They identified all children with a diagnosis of autism. They also identified children of similar age and sex who did not have autism. The investigators then looked to see how many children in each group lived near power lines before they were diagnosed with autism.

A. Randomized controlled trial (RCT)

B. Prospective cohort C. Retrospective cohort D. Case-control E. Case series

Randomize

d contro

lled tr

...

Prosp

ectiv

e cohort

Retrosp

ectiv

e cohort

Case-co

ntrol

Case se

ries

20% 20% 20%20%20%

In a study of risk factors for the development of autism, investigators performed a thorough literature search for all studies assessing environmental exposures and childhood autism. The investigators then reported the results of the studies which met their inclusion/exclusion criteria. The results could not be combined for statistical analysis.

A. Randomized controlled trial (RCT)

B. Prospective cohort C. Retrospective cohort D. Meta-analysis E. General review F. Systematic review

Randomize

d contro

lled tr

...

Prosp

ectiv

e cohort

Retrosp

ectiv

e cohort

Meta

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is

General r

eview

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matic

revie

w

17% 17% 17%17%17%17%

In a study of risk factors for the development of autism, last month investigators accessed records from MindLinc from 2000-2008. The investigators determined which children lived near power lines at the time of their birth. They then looked to see which children developed autism by their 5th birthday.

A. Randomized controlled trial (RCT)

B. Prospective cohort

C. Retrospective cohort

D. Case-control

E. Meta-analysis

F. Systematic review Random

ized co

ntrolle

d tr...

Prosp

ectiv

e cohort

Retrosp

ectiv

e cohort

Case-co

ntrol

Meta

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is

Syste

matic

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17% 17% 17%17%17%17%

Jamie Fox, MD, Pediatric Emergency Medicine

Jamie Fox, MD, Pediatric Emergency Medicine

Jamie Fox, MD, Pediatric Emergency Medicine

Jamie Fox, MD, Pediatric Emergency Medicine

Jamie Fox, MD, Pediatric Emergency Medicine