Evidence Based Medicine D.J. Van Durme, MD Evidence Based Medicine in the office and hospital Daniel J. Van Durme, MD Professor and Chair Dept. of Family

Evidence Based Medicine D.J. Van Durme, MD

Evidence Based Medicine Evidence Based Medicine in the office and hospitalin the office and hospital

Daniel J. Van Durme, MD Professor and Chair Dept. of Family Medicine and Rural Health


Who is this guy and what does he know? Private practice in semi-rural Pasco county

(north of Tampa) 1991-1996 Faculty at University of South Florida College of

Medicine 1989-1991 and 1996-2004 Still seeing patients at Madison County Health

Department Creator, Course Director, and lecturer for

“Evidence Based Medicine” course at USF COM 40 hours of lecture and small group for Med 2’s


I am NOT an EBM expert

Expert – from Latin “ex” – has been “spurt” – a drip under pressure

I struggle with stats I am often overwhelmed with the volume of

medical information and the need to critically review the important stuff

BUT – I can still provide high quality Evidence Based Care


Learning Objectives for today

At the conclusion of today’s session, the learner should be able to: Define evidence based medicine Demonstrate an ability to formulate a patient-oriented

clinical question from a clinical scenario Discuss appropriate search strategies for finding

answer(s) to clinical questions Demonstrate the use of PDA and computer resources

for finding high quality evidence based answers Discuss how evidence based findings would be

applied to the care of a patient


EBM: Original “Official” Definition

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

Evidence-Based Medicine Working GroupSackett et al circa 1996


Problems with EBM definition

EBM has been accused of being . . . Cookbook medicine

“It takes away the art of medicine or the clinical judgment” WRONG – the research results may not be applicable or

appropriate for a given patient

Cost-Cutting medicine “It is all a plot by managed care companies to cut cost of

care and increase their profit share” WRONG - When you find what is best for a given patient it

may cost more OR it may save money


Problems with EBM (cont.) …

EBM has been accused of being . . . Impossible or impractical

“There is no way I can spend hours looking for and critically reviewing medical articles for each of the patients that I see.”

WRONG – there are many tools available at the point of care (PDA’s and computers and texts) that can help you find answers in a matter of 1-2 minutes.


Better – EBM definition

The integration of best research evidence with

clinical expertise and

patient valuesSackett et al 2000



Two Fundamental Principles of true Evidence Based Practice

1. Clinical Decision Making: 1. Evidence is Never Enough

a. Treatment of Pneumococcal pneumonia SHOULD be different for:Terminal Cancer PatientElderly, Severely Demented PatientYoung, mother of 2 children

b. Importance of Values/Preferences


Two Fundamental Principles of EBM

2. A hierarchy of evidencea. There is a hierarchy of possible informationb. Look for the highest level of evidence

available

BE ready to change your approach or management when a higher level of evidence contradicts your experience

“Experience Based Medicine” – doing the wrong thing with increasing confidence for an impressive number of years.


Best research evidence Clinically relevant – not just “well-done research” Ideally patient-centered clinical research

What matters to patients? Morbidity, mortality, quality of life

POEM Patient Oriented Evidence that Matters Matters to my practice and my patients

Sometimes disease-oriented evidence (DOE) How many irregular heartbeats per hour? Can be misleading (sometimes dangerously so)

Occasionally basic science What is the level of C-reactive protein (CRP) in the serum? Can be VERY misleading


Clinical Expertise Use of clinical skills and past experience Identification of individual patient’s . . .

Health status and health risks Personal values and expectations (Probable) diagnosis

Knowledge of disease prevalence, access to medical or test availability, etc. in your community

Did you ask the correct clinical question(s)?


Patient values

Patient preferences and concerns Cultural influences Religious/spiritual influences Psychosocial issues

May include . . . Reimbursement or insurance status Access to care Societal factors Other influences


Why do we need EBM?

Stay up to dateMedical information

changes constantly Unlike bread – our

knowledge does not become visibly moldy or stale – we just keep using it


Why do we need EBM?

Save LIVES! Encainide and flecainide for ventricular arrhythmia

Well proven to decrease the number of premature ventricular beats – became widely used 1980’s

BUT Further studies showed significant INCREASE in MORTALITY –

died from other cardiac complications and dysrhythmias ( a dangerous “DOE”)

Thrombolytics for acute MI CLEAR evidence of benefit in the 1970’s Not widely recommended until 1988 – almost 13 yrs later How many thousands of people died unnecessarily in the years in

between?


Why do we need EBM?

We want to do the “right thing” – what is “best” for our patients

Practice variations that do not make sense . . .Not to doctorsNot to patientsNot to payorsNot to policy makers


Assessment of Radical Prostatectomy: Time Trends, Geographic Variation, and Outcomes

Lu-Yao: JAMA, Volume 269(20). May 26, Lu-Yao: JAMA, Volume 269(20). May 26, 19931993..


So why not get info from textbooks and review articles? Texts and review articles?

Dated – perhaps by several yearsOften heavily biased

Author chooses article that he/she agrees with (or has written)

May help more with background knowledge (help me learn about disease) not foreground (help me answer the specific clinical question for this patient)


Foreground questions

Background questions

Medical studentExperienced clinician


But how does EBM REALLY work?

Step 1: Translate clinical scenarios into an answerable clinical questionsTRUE STORY –My 54 yr old patient was just diagnosed with

prostate cancer I received pathology report and he is coming

in to see me tomorrow


What are my questions?

What do I know about prostate cancer? How common is it? Is it usually aggressive and rapidly fatal? How can it be treated – surgery, chemotherapy,

radiation? What about family history – what should I tell him

about his son’s risk? Etc. These are called “background” questions


Foreground questions apply to that specific patient (or population) After meeting with patient and spouse we find that

he has seen the urologist who recommended surgery but the patient is reluctant 54 year old male patient was diagnosed with

intermediate grade prostate cancer and wants to know whether to get a radical prostatectomy or radiation treatment. He is concerned about death from prostate CA and also risks of impotence and incontinence.


Question?

Population: For middle aged males with intermediate stage

prostate cancer, Intervention:

Treated with radical prostatectomy Comparison:

Compared to radiation treatment Outcome:

What are the rates of incontinence, impotence and cancer-related mortality?


Developing the question requires:Some background knowledge of the conditionUnderstanding of the patient and what are the

outcomes that matter in this patient Death? Disability? Quality of life? – Anxiety, Impotence, etc. Cost?


Hands on – Part 1

Think in your practice THIS week – what was a clinical question you had? Think of a foreground question (not just a drug dose

or drug interaction) What diagnostic test would have been best for that pt with

abdominal pain? What treatment would have been best for the pt with

Parkinsons? What about the patient who was asking about acupuncture

for osteoarthritis?


How does EBM REALLY work?

Step 2: Translate question into effective searches for the best evidenceRequires knowledge of medical informaticsHow to search – what terms to use, what

types of studies, etc.Where to search – utility of varied sources of

information Evidence based sources, Texts, Medline,


Purpose-specific resources

CDC Travel Drug information resources Patient Education handouts Medical Search engines Textbooks Journals


EBM sources

EBM sources – Cochrane, USPSTF, Clinical Evidence+ Ideally best information source – hard to

argue with, will explicitly state the level of evidence (weak to strong)

- There may not be any “good” evidence


How does EBM REALLY work? Step 3: Critically appraise the evidence

Validity of the evidence Internal – study design, blinding, randomized, sample size,

appropriate statistics, etc. Relevance of the evidence

Did they measure something pts care about? Is population similar (enough) to mine? Is the intervention feasible?

Importance of the evidence Magnitude of effect or clinical significance? P values, confidence intervals, relative risk or absolute risk

reduction


Step 3: Critically appraise the evidence (cont.)

Requires some knowledge of basic epidemiology and biostatistics Sensitivity, specificity, prevalence, likelihood ratios Absolute risk reduction, relative risk reduction, odds

ratios, number needed to treat Requires knowledge of study types

ASSUMING THAT IT IS A WELL DESIGNED STUDY Appropriate sample size, randomization, stats, treatment

allocation, etc., etc. Meta-analysis of RCT’s > RCT > Cohort > Case

Control > Case Series > Case Report


Hierarchy of studies


Step 3 – Critical appraisal of medical literature This is often confused with EBM

they are not the same thing This is often the toughest part of EBM Skipped by many doctors suffering from

photonumerophobia The fear that one’s fear of numbers and statistics will

come to light This is where most attempts come to a halt

Not enough time and expertise


EBM Databases

Systematic Literature Searches• Cochrane Library (OVID)• Clinical Evidence

Systematic Literature Surveillance• ACP Journal Club (OVID)• DARE• DynaMed • Medical InfoRetriever• Journal of Family Practice POEMS

EMB Search Engine• TRIP Database


Drilling for the Best Information

Cochrane Library

Specialty-specificPOEMs

ACP Journal Club

Clinical EvidenceClinical Inquiries

Textbooks, Up-to-Date, 5-Minute Clinical Consult

Use

fuln

ess

Journals/ MedlinePubMed


Cochrane Library

The current resource with the highest methodological standards

For each clinical question, all of the English literature meticulously searched for randomized trials

Large systematic reviews with valid methods + collaborative effort

Conclusions are based on all the evidence from valid randomized trials


Cochrane Library Included in OVID subscription Limitations

limited to English only addresses questions amenable to randomized

trials most of medicine has not been studied enough to

allow for conclusions $235/year or abstracts only


InfoRetriever 104 journals surveyed for Evidence-Based Practice

Newsletter Over 1300 article synopses/ POEMS Cochrane abstracts Selected evidence-based guidelines (USPSTF, CDC,

others) Basic drug info ICD-9 codes Clinical calculators/prediction rules


InfoRetriever Symbols


InfoRetriever Comes in web, desktop and PDA versions Explicitly states Levels of Evidence Limitations

individual article summaries may not account for the “big picture”

may have to read multiple items $249/year Optimized for use with Internet Explorer 5.x or

Netscape 6.x


Hands on with InfoRetriever

1. Look up “migraine”5 min clinical consult – level 5 evidence

Background infoOverview: practice guidelines

ACEP – guidelines for EDTx: Drug treatment – anticonvulsants?

Note symbols for Cochrane database or InfoPOEM Info available on CAM, screening, Pt ed, etc


Levels of Evidence

Level 1: Randomized Clinical Trials

Level 2: Head to Head Trial or

Systematic Review of Cohort

Studies

Level 3: Case-Control Studies

Level 4: Case-series

Level 5: Expert Opinion


Guidelines What is a guideline? Guidelines may be

Explicitly evidence-basedEvidence-basedResearch-based (highly referenced)Opinion-based“expert consensus”


Guidelines National Guideline Clearinghouse Primary Care Clinical Practice Guideline

s Agency/Association sites

AAFPAAPACS


Clinical Evidence BMJ Summaries of Evidence Specific clinical questions: treatment Makes specific recommendations States when there is a lack of evidence Free from United Health Foundation


Clinical Evidence


Hands On with Clinical Evidence Look up Stroke Prevention in Clinical

EvidenceBeneficial – control BP and cholesterol and

give aspirinUnknown – other antiplatelet agents showed

no benefit over aspirin Ineffective or harmful – anticoagulant for

those in sinus rhythm & carotid endarterectomy for those with <30% symptomatic stenosis


Hands on (POSSIBLE example or use your own!)

Patient wants to know if Gingko biloba will help her mom’s Alzheimer’sSee InfoRetriever – dementia

Treatment – Complementary and alternative medicine

Mixed results in InfoPOEMS – some say maybe yes, some say no

Cochrane says – it seems safe, but studies are weak, we really do not know – more study is needed

See Clinical Evidence - dementia


ACP Journal Club

About 100 journals systematically surveyed Highest-validity articles abstracted Structured abstracts to guide critical appraisal Clinical commentary Included in our OVID subscription


ACP Journal Club

Limitations individual article summaries may not account for the

“big picture” may have to read multiple items No “control” over what is covered $78/year ?


Need to read the “key”

Levels of EvidenceLevel 1: HighestLevel 2: Level 3:Level 4:Level 5: Lowest—but still evidence


Read the “key”

Levels of Recommendation (USPSTF) A – Highest – Strongly recommended (PAP smears) B – Recommended (Mammograms age 40+) C – no recommendation for or against (too close a

balance between harm/benefit) (osteoporosis screening below age 60)

D – Recommend AGAINST (ovarian cancer) I – insufficient evidence to make any recommendation

for or against (Prostate cancer screening)


Other guidelines

A – good evidence B – fair evidence C – based on expert opinion and/or

consensus X – evidence of harm


Essential principle

Be ready to “surrender” to a higher level of evidence when it becomes available

Do not become entrenched in what has been done for years A bad idea done by a LOT of people for a LONG time,

is still a bad idea


Evidence based information, recommendations, reviews Not all that claims to be “evidence based”, is really EBM

Should include explicit statements about search methods, findings, appraisal and level of evidence (or strength of recommendation)

High quality sources Cochrane, AHRQ, USPSTF, ACP Journal Club, Clinical

Evidence, InfoRetriever Questionable sources

Developed by BOGSAT methodology Bunch Of Guys Sitting Around a Table Sometimes called “consensus”, argument may be won based on

volume and stamina



Step 4: Implement information into practice Integrate information with patients values and

preferencesPatient-centered care



Step 4: Implement information into practice Integrate information with patients values and

preferences Patient-centered care

Demographics, age, socioeconomics, fear, etc. Evidence may point to surgery as better treatment but

patient refuses This does NOT mean EBM is out the window Your job is to understand the magnitude of benefit and the

level of evidence Then translate into useable information for the patient


As patient participates in care decisions, you are practicing TRUE evidence based medicine


OK – I am convinced, how can I start to practice evidence based medicine?

Step 1 – Ask the questions Use your clinical experiences to find 1-2 case

scenarios every day that translate into clinical questions

Ask your student to help – he/she may REALLY appreciate that you explicitly tried to help find a REAL answer that would help an actual patient

PICO – population – intervention – comparison - outcome


Use your growing clinical skills but do not be swayed by YUCK’sYour Unsubstantiated Clinical Knowledge

(and experience)Regularly seek to find the best available

evidence to guide youEspecially review common topics, you may be

getting “stale” without realizing it


Step 2 – Search for the evidence When searching for background

informationCritically appraise your texts for known

problems/biases Date of publication, references, source

Try to use systematic review articles Explicit statements of how and where they

searched, and statements of strength of recommendation of level of evidence


Step 2 – searching (continued) Locate and regularly use YODA’s

Your Own Data Analyzer Let others do hard work for you

It is their full-time job, do you really have the time and expertise to do better?

Try InfoRetriever and Clinical Evidence a few times a week Save your questions on a card and find answers over lunch or end of

the day Look at the Cochrane reports first BUT even those may be dated!


Step 3 – Critical Appraisal Do not fall for three common myths

Newer article, by “bigger” name, and a “famous” journal, does NOT mean it is better

Use three quick tips Is it relevant first?, don’t get overwhelmed by the stats, was it

from YODA?

PRACTICE CRITICAL APPRAISAL of original research – if you do not use it, you will lose it

I often let headlines drive this – then I need to know NOW


Step 4 – Integrate into patient careTake your findings back to your patients

Sometimes this may be 2 minutes later or 2 weeks later

Discuss how to integrate this into care of your patient

Tell the patient that you have been “looking up the latest information” and they will appreciate it!


Step 5 – Self evaluation – how did you do?Learn to improve your . . .

Framing of the question Search terms Search locations Critical appraisal skills Patient understanding Patient centered approach


Questions?

Documents

Evidence Based Medicine D.J. Van Durme, MD Evidence Based Medicine in the office and hospital Daniel J. Van Durme, MD Professor and Chair Dept. of Family