understanding concepts of evidenced based medicine

Understanding concepts of Understanding concepts of Evidenced Based MedicineEvidenced Based Medicine

Frank J. Domino, M.D.Frank J. Domino, M.D.

ProfessorProfessor

University of Massachusetts Medical University of Massachusetts Medical SchoolSchool

Learning ObjectivesLearning Objectives by the end of the session, you will by the end of the session, you will

Appreciate the basic statistical concepts Appreciate the basic statistical concepts involved in EBM involved in EBM

Contrast absolute risk reduction (ARR) Contrast absolute risk reduction (ARR) with relative risk reduction (RRR) and with relative risk reduction (RRR) and

Calculate the number needed treat (NNT); Calculate the number needed treat (NNT); and and

Understand how sometimes statistical Understand how sometimes statistical interpretation can leads us astray….interpretation can leads us astray….

Outline of TalkOutline of Talk

1.1. Types of Papers in the Medical LiteratureTypes of Papers in the Medical Literature1.1. Review vs. Systematic ReviewReview vs. Systematic Review

2.2. RCT, Cohort, Case-Control StudiesRCT, Cohort, Case-Control Studies

3.3. BiasBias

2.2. Statistics: AR, RR, RRR, NNTStatistics: AR, RR, RRR, NNT

3.3. Patient vs Disease Oriented EvidencePatient vs Disease Oriented Evidence

4

What is Evidence-Based Medicine?What is Evidence-Based Medicine?

Integration ofIntegration of

• Best research evidence Best research evidence (from Systematic (from Systematic Reviews)Reviews)

• Clinical expertiseClinical expertise

• Patient valuesPatient values

Patient Oriented Outcomes [POEPatient Oriented Outcomes [POE] ] vs Disease/Intermetdiate Outcomes vs Disease/Intermetdiate Outcomes [DOE][DOE]

Sacket et al “How to Teach and Practice EBM”, Churchill Livingston, 2000 Len

Patient

Values

Types of Research Types of Research InformationInformation

Review ArticlesReview Articles

VsVs

Systematic ReviewsSystematic Reviews

Traditional Review ArticleTraditional Review Article - - Summary of the literatureSummary of the literature

Often valuable reviews Often valuable reviews

for medical practicefor medical practice

Problems:Problems: Do not Do not necessarilynecessarily include all relevant include all relevant

evidenceevidence Author bias mixed with the evidenceAuthor bias mixed with the evidence Publisher’s motives in ?Publisher’s motives in ?

A A Systematic ReviewSystematic Review Article Article– – Utilizes quality standards to judge the literatureUtilizes quality standards to judge the literature

Clear objective for evaluation of studyClear objective for evaluation of study Identify studies (Identify studies (Randomized Controlled Randomized Controlled

TrialsTrials) meeting review criteria ) meeting review criteria The results of acceptable studies combinedThe results of acceptable studies combined Outcome of those studies publishedOutcome of those studies published If Quantitative, combined -> Meta AnalysisIf Quantitative, combined -> Meta Analysis

Systematic ReviewSystematic Review

Systematic ReviewMeta Analysis

Antibiotics and Acute SinusitisAntibiotics and Acute SinusitisA Cochrane A Cochrane SystematicSystematic Review Review

www.cochrane.orgwww.cochrane.org

1. Objectives:1. Objectives: ‘To determine whether ‘To determine whether antibiotics are indicated for acute sinusitis, antibiotics are indicated for acute sinusitis, and if so, which antibiotic classes are most and if so, which antibiotic classes are most effective.’effective.’

2. Search strategy:2. Search strategy: Studies identified via Studies identified via searches of MEDLINE & EMABASE, contacts searches of MEDLINE & EMABASE, contacts w/ pharmaceutical companies and w/ pharmaceutical companies and bibliographies of included studies.bibliographies of included studies.

3. Selection criteria 3. Selection criteria

Randomized controlled trials n Randomized controlled trials n >> 30 adults. 30 adults. Compare antibiotic to control or other Abx.Compare antibiotic to control or other Abx. DX confirmed by radiograph or aspiration. DX confirmed by radiograph or aspiration. Outcomes: cure or symptom improvement.Outcomes: cure or symptom improvement.

Of Of 20582058 potentially relevant studies, potentially relevant studies, onlyonly 49 stu49 studies (13,660 pts) met review criteria! dies (13,660 pts) met review criteria!

> 2000 of questionable significance……..> 2000 of questionable significance……..

4. Data Combined 4. Data Combined Reviewers' conclusions:Reviewers' conclusions:

• For acute maxillary sinusitis, current For acute maxillary sinusitis, current evidence is evidence is limitedlimited but supports penicillin but supports penicillin or amoxicillin for 7 to 14 days. or amoxicillin for 7 to 14 days.

• Clinicians should weigh the moderate Clinicians should weigh the moderate benefits of antibiotic treatment against benefits of antibiotic treatment against the potential for adverse effects.the potential for adverse effects.

The Cochrane Library,The Cochrane Library, Oxford Oxford

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The Forest PlotThe Forest Plot

Estimate and confidence interval for each study

Estimate and confidence for the meta-analysis

Direction of effect

Scale (effect measure)

Line of no effect

Estimates with 95% confidence intervals

0.2 1.0 5

Favours LR Favours control

Risk ratio

Kennedy 1997

Locke 1952A

Lopes 1997

Reynolds 1998

Seiberth 1994

Forest Plot: If <> to your Left, Intervention was Effective at Lowering Risk of Outcome.

Len

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Interpreting a Meta Analysis using a Forest Plot

Len

Study DesignsStudy Designs

The Systematic Reviews use:The Systematic Reviews use:

1. Randomized Controlled Trials1. Randomized Controlled Trials

Other Study types: Other Study types:

2. Cohort Studies2. Cohort Studies

3. Case Control Studies3. Case Control Studies

Randomized Controlled Clinical TrialsRandomized Controlled Clinical Trials

A population is chosen, then randomly A population is chosen, then randomly assigned to an intervention or notassigned to an intervention or not

An An interventionintervention is given to the is given to the study study population.population.

The Non-InterventionThe Non-Intervention group group receives a receives a placebo or some standard of care.placebo or some standard of care.

Differences in pre identified outcomes are Differences in pre identified outcomes are measured and produce measured and produce

ABSOLUTE RISK of those outcomesABSOLUTE RISK of those outcomes

Randomized Controlled Trials Randomized Controlled Trials Bias in the Medical LiteratureBias in the Medical Literature

Attrition bias – Attrition bias – how were “drop outs” how were “drop outs” accounted foraccounted for

Publication biasPublication bias – only positive results get – only positive results get publishedpublished

Comparator bias Comparator bias - new Tx compared to - new Tx compared to placebo rather than current standardplacebo rather than current standard

Commercial BiasCommercial Bias – who funded the study – who funded the study and what motivated the researchersand what motivated the researchers

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Attrition BiasAttrition Bias

What happened to What happened to everyoneeveryone who who was randomized?was randomized?

Was the study “Intention to Treat”?Was the study “Intention to Treat”?

May need to review the data to May need to review the data to determine if they “add up”determine if they “add up”

Bob

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Publication BiasPublication BiasFactors that prevent publicationFactors that prevent publication40% of All RCT not published40% of All RCT not published

RCT of using 400 IU/day of Vitamin E to RCT of using 400 IU/day of Vitamin E to prevent Coronary Artery Diseaseprevent Coronary Artery Disease. .

InterventionIntervention PlaceboPlacebo

MIMI 4.24.2 3.9 3.9 p=0.7p=0.7

No benefit to supplementing diet with No benefit to supplementing diet with Vitamin E in the prevention of CADVitamin E in the prevention of CAD

Bob

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Comparator BiasComparator BiasComparing new treatment to no treatment, Comparing new treatment to no treatment,

rather than the current standard of carerather than the current standard of care

““Azithromycin is superior to Azithromycin is superior to placebo in the treatment of placebo in the treatment of Acute Sinusitis”Acute Sinusitis”

That is nice, but is it superior That is nice, but is it superior to Amoxicillin? Don’t know; to Amoxicillin? Don’t know; they didn’t do (or won’t they didn’t do (or won’t publish) that study.publish) that study.

Bob

Commercial BiasCommercial Bias

Look for Disclosures of Look for Disclosures of the Authors the Authors

Who funded the studyWho funded the study Bottom of The Front Bottom of The Front

page and page and just before Reference Sectionjust before Reference Section

Ex. JUPITER StudyEx. JUPITER Study

20BIAS: Assume it is Present Bob

P < 0.001

Statistically significant!

AR MI placebo - 0.76%AR MI Crestor - 0.35%

Cohort StudiesCohort Studies

Prospective, ObservationalProspective, Observational studies with conclusions studies with conclusions

Produces aProduces a Relative Risk (Relative Risk (RRRR))RR=Incidence of disease in RR=Incidence of disease in ExposedExposed

divided by Incidence of disease in divided by Incidence of disease in Unexposed Unexposed populationpopulation

Ex: Framingham Heart studyEx: Framingham Heart study

Relative Risk (Relative Risk (RRRR))

If If < 1.0< 1.0, risk is REDUCED, risk is REDUCED

If If > 1.0> 1.0, risk is INCREASED, risk is INCREASED

RR = Number of times more or less than 1 an event will happen in one group when compared to another

““The RR of death if involved in The RR of death if involved in an MVA without a seat belt = an MVA without a seat belt =

3.5”3.5”

“Tea drinkers have a 0.6 RR of dying from CAD”

CorrelationCorrelationdoes not does not prove prove cause and effect!cause and effect!

Does tea Does tea drinking drinking prevent prevent CAD???CAD???

Vitamin E & CADVitamin E & CAD3 3 cohort studiescohort studies mid-90’s concluded mid-90’s concluded vitamin E use vitamin E use correlatedcorrelated with a lower with a lower

risk risk for CAD. for CAD.

1.1. Antioxidant Vitamins and Coronary Heart Antioxidant Vitamins and Coronary Heart DiseaseDisease

2.2. Vitamin E Consumption and Risk of Coronary Vitamin E Consumption and Risk of Coronary Disease in MenDisease in Men

3.3. Vitamin E Consumption and Risk of CAD in Vitamin E Consumption and Risk of CAD in WomenWomen

The Heart Outcomes PreventionThe Heart Outcomes PreventionEvaluation (HOPE) Study Evaluation (HOPE) Study

2000:2000: Controlled TrialControlled Trial of Vitamin E for 5 Yr of Vitamin E for 5 Yr::

rates of MI, CVA & CV death did not differ rates of MI, CVA & CV death did not differ significantly from placebo (16.2% v 15.5 %).significantly from placebo (16.2% v 15.5 %).

•HOPE II (JAMA 2005) Long-term use of vit E in HOPE II (JAMA 2005) Long-term use of vit E in CHD or DM patients does not prevent cancer or CHD or DM patients does not prevent cancer or major cardiovascular events major cardiovascular events and may increase and may increase

the risk for HFthe risk for HF

Case Control StudiesCase Control Studies

Identify a Potential trend in diseaseIdentify a Potential trend in disease Collect exposure history of “CASES”Collect exposure history of “CASES” Identify similar people age/gender Identify similar people age/gender

like Cases but without diseaselike Cases but without disease Compare Cases to Controls to Compare Cases to Controls to

determine if exposure increased determine if exposure increased ODDS of disease.ODDS of disease.

Ex: Cigarette smokingEx: Cigarette smoking

Outline of TalkOutline of Talk

1.1. Types of Papers in the Medical LiteratureTypes of Papers in the Medical Literature1.1. Review vs. Systematic ReviewReview vs. Systematic Review

2.2. RCT, Cohort, Case-Control StudiesRCT, Cohort, Case-Control Studies

3.3. BiasBias

2.2. Statistics: AR, RR, RRR, NNTStatistics: AR, RR, RRR, NNT

1.1. Patient vs Disease Oriented EvidencePatient vs Disease Oriented Evidence

Which drug would you take?Which drug would you take?

Drug A Drug A can reduce your MI risk by 1/3can reduce your MI risk by 1/3 Drug B Drug B can reduce your MI risk by 9 %can reduce your MI risk by 9 % Drug C Drug C every 11 patients who take every 11 patients who take

Drug C, one MI will be preventedDrug C, one MI will be prevented

A B C

The Scandinavian Simvastatin Survival The Scandinavian Simvastatin Survival Study (4S)Study (4S)

4444 pts with angina or previous MI and ↑ 4444 pts with angina or previous MI and ↑ cholesterolcholesterol

Randomized to simvastatin or placebo. Randomized to simvastatin or placebo. After 5 yrs, simvastatin reduced TC 25%, After 5 yrs, simvastatin reduced TC 25%,

LDL 35% and increased HDL 8%. [DOE]LDL 35% and increased HDL 8%. [DOE]

MI or death:MI or death:

622(622(28%)28%) control group (p control group (placebo)lacebo)

431pts431pts (19%) simvastatin group [POE] (19%) simvastatin group [POE]

Disease Oriented vs. Patient Oriented Disease Oriented vs. Patient Oriented EvidenceEvidence

DOEDOE

Lidocaine Lidocaine ↓ ↓ V. Tach V. Tach

HRT will HRT will ↓↓ LDL; LDL;

↑↑ HDLHDL

Fluoride Fluoride ↑↑ bone bone densitydensity

POEPOEProphylactic Lido Prophylactic Lido ↑↑ CV CV

deathdeath

Increased risk of stroke Increased risk of stroke & Mortality& Mortality

Does not prevent Does not prevent fracturesfractures

Absolute Risk Reduction (Absolute Risk Reduction (ARRARR))

4S Trial: The 4S Trial: The differencedifference between the between the incidence of outcome in the incidence of outcome in the controcontrol l

group (28%) and the incidence in the group (28%) and the incidence in the treatment group (19%). treatment group (19%).

ARRARR = Incid Control – Incid Treatment = Incid Control – Incid Treatment

28%- 19% = 9% ARR28%- 19% = 9% ARR

Relative Risk ReductionRelative Risk Reduction

Absolute Risk Reduction (ARR) Absolute Risk Reduction (ARR) divided by divided by

Incidence in the control groupIncidence in the control group

RRRRRR = (28-19)/28 = 33% = (28-19)/28 = 33%

RRR is not the same as AR or RRRRR is not the same as AR or RR

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Relative Risk ReductionRelative Risk Reduction

A way to describe (and often over A way to describe (and often over inflate) the relative impact of a inflate) the relative impact of a treatment on an outcometreatment on an outcome

Bob

Number Needed to Treat (NNT)Number Needed to Treat (NNT)

NNT NNT - the number of people needed to - the number of people needed to receive an intervention before one person receive an intervention before one person gets the expected outcome!gets the expected outcome!

NNT = 100 divided by NNT = 100 divided by Absolute Risk Absolute Risk ReductionReduction..

NNT NNT = 100/(28-19) = 11= 100/(28-19) = 11

11 pts w/ CAD need to be treated with 11 pts w/ CAD need to be treated with simvastatin to prevent 1 from having a simvastatin to prevent 1 from having a subsequent MI or death.subsequent MI or death.

Which drug would you take?Which drug would you take?

Drug A Drug A can reduce your MI risk by 1/3can reduce your MI risk by 1/3rdrd

• Relative Risk Reduction (Relative Risk Reduction (RRR =RRR = 33%) 33%)

Drug B Drug B can reduce your MI risk by 9%can reduce your MI risk by 9%• Absolute Risk Reduction (Absolute Risk Reduction (ARRARR = 9 %) = 9 %)

Drug C Drug C prevent an MI for every 11 prevent an MI for every 11 patients who take it regularlypatients who take it regularly• Number Needed to Treat (Number Needed to Treat (NNTNNT = 11) = 11)

Another example of NNT:Another example of NNT:Does alendronate prevent hip fractures in Does alendronate prevent hip fractures in

postmenopausal women ?postmenopausal women ?

The published study:The published study: Low bone mass densityLow bone mass density One or more fractures at baselineOne or more fractures at baseline Alendronate 5 mg/d x 24 mo, then Alendronate 5 mg/d x 24 mo, then

10mg/d10mg/d Outcome - subsequent hip fracturesOutcome - subsequent hip fractures

OutcomesOutcomes

P < 0.044 P < 0.044 Statistically Statistically

significant!significant!

Statistical Significant does NOT equal Clinical Significant

Statistical SignificanceStatistical Significance

An indication that the findings are An indication that the findings are not not due to chance!due to chance!

P < 0.05 means there is < 5% chance P < 0.05 means there is < 5% chance the difference between the placebo the difference between the placebo and treated group is a chance and treated group is a chance occurrence.occurrence.

It is It is not annot an implication of implication of clinicalclinical meaning (significance).meaning (significance).

A Closer Look…A Closer Look…

Hip fracture rate in Hip fracture rate in treated group - 1%treated group - 1%

Hip fracture rate in control group - 2.2%

Absolute Risk ReductionAbsolute Risk Reduction

Placebo incidence – Treated incidencePlacebo incidence – Treated incidence

2.2% - 1% = 1.2%2.2% - 1% = 1.2%

A A high riskhigh risk patient can reduce patient can reduce her risk of a hip fracture by her risk of a hip fracture by

1.2% from alendronate x 4 yrs 1.2% from alendronate x 4 yrs

What happens to the other 82 women?What happens to the other 82 women?

They receive the medication, They receive the medication, incurring the cost of treatment along incurring the cost of treatment along with the exposure to the potential with the exposure to the potential side effects, but…..side effects, but…..

obtained obtained nono identified identified benefit!benefit!

What is this 56% ???What is this 56% ???

RelativeRelative Risk Risk Reduction Reduction

2.2-1(ARR)/2.2 = 56%2.2-1(ARR)/2.2 = 56%

Number Needed to TreatNumber Needed to Treat

100/ARR = 100/(2.2-1) = 83100/ARR = 100/(2.2-1) = 83

83 83 high riskhigh risk women would have women would have to be treated with alendronate to be treated with alendronate for 3 years to prevent one for 3 years to prevent one additional hip fractureadditional hip fracture

Evidence-Based MedicineEvidence-Based Medicine

What’s a What’s a “good”“good” NNT ? NNT ?

Depends on Depends on risksrisks of intervention vs of intervention vs outcomeoutcome

The best NNT would be 1 - every The best NNT would be 1 - every treated patient benefited, but no treated patient benefited, but no placebo benefitplacebo benefit

NNTs NNTs << 5 indicate very effective 5 indicate very effective treatmentstreatments

Good NNTGood NNT NNT is a VALUE BASED decisionNNT is a VALUE BASED decision NNTs of 50 or 100 useful for NNTs of 50 or 100 useful for

interventions to reduce death after interventions to reduce death after heart attack.heart attack.

NNS in the 1000’s as screened NNS in the 1000’s as screened population includes those with and population includes those with and without disease.without disease.

Decisions should also consider costs Decisions should also consider costs and risk of the intervention (NNH)and risk of the intervention (NNH)

Some NNTsSome NNTsPrevent 1Prevent 1 DrugDrug NNTNNT

MI/DeathMI/Death ASA X 1 yearASA X 1 year 500 healthy 500 healthy ♂♂

Stroke/MI/DeathStroke/MI/Death

DeathDeath

Acute Rheumatic Acute Rheumatic feverfever

Hip FxHip Fx

25 unstable angina

15 severe HTNAnti-HTN X 1yrAnti-HTN X 1yr

ACEiACEi

PenicillinPenicillin

Ca/Vit D X 3yrCa/Vit D X 3yr

700 mild HTN 700 mild HTN

18 CHF/post-MI18 CHF/post-MI

3500 strep throats3500 strep throats

30 ambulatory30 ambulatory♀♀

Number Needed to Harm?Number Needed to Harm?

DrugDrug NNTNNT NNHNNH

Prevent 1 Hip FxPrevent 1 Hip Fx

HRT X 5yrsHRT X 5yrs

333 333 ♀♀

Cause 1 StrokeCause 1 Stroke 250 ♀250 ♀

Cause 1 Breast CaCause 1 Breast Ca 200 ♀200 ♀

Cause 1 DVTCause 1 DVT 100 ♀100 ♀

OM pain reliefOM pain relief

Antibiotic X Antibiotic X 10 days10 days

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Cause VomitingCause Vomiting 1212

Cause DiarrheaCause Diarrhea 1212

Cause a RashCause a Rash 1212

Crestor for Low Risk PatientsCrestor for Low Risk Patients

AR MI with placebo - 0.76%AR MI with placebo - 0.76%

AR MI with Crestor - AR MI with Crestor - 0.35%0.35%

ARR = 0.76-0.35 =0.41%ARR = 0.76-0.35 =0.41%

RRR= 0.41/0.76 = 54%RRR= 0.41/0.76 = 54%

NNT = 100/0.41 = 244 NNT = 100/0.41 = 244

244 low risk patients would have to be 244 low risk patients would have to be treated with rosuvastatin for 2 years to treated with rosuvastatin for 2 years to prevent one MIprevent one MI

What happens to the other 243 What happens to the other 243 patients?patients?

They receive the medication, They receive the medication, incurring the cost of treatment along incurring the cost of treatment along with the exposure to the potential with the exposure to the potential side effects, but…..side effects, but…..

obtained obtained nono recognized recognized benefit!benefit!

Solving Questions on the Fly:Solving Questions on the Fly:Using Best EvidenceUsing Best Evidence


ProfessorProfessor

Dept. Family Medicine & Community Dept. Family Medicine & Community HealthHealth

University of Massachusetts Medical University of Massachusetts Medical SchoolSchool

Worcester, MassachusettsWorcester, Massachusetts

[email protected]@umassmemorial.org

5555

Objectives:Objectives:

1.1. Understand what characteristics Understand what characteristics denote “Best” medical evidencedenote “Best” medical evidence

2.2. Appreciate spectrum of resources Appreciate spectrum of resources available to use at bedside or with available to use at bedside or with E.M.R.E.M.R.

3.3. Solve your questions in real timeSolve your questions in real time

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Why this session?Why this session?

President Obama January 2009:President Obama January 2009: Provision of $40,000 in incentives Provision of $40,000 in incentives

(beginning in 2011) for physicians to (beginning in 2011) for physicians to use an EHRuse an EHR

Funds to coordinate interoperable EHRs Funds to coordinate interoperable EHRs Education programs to train in EHR useEducation programs to train in EHR use Creation of HIT grant and loan programs Creation of HIT grant and loan programs Acceleration of the construction of the Acceleration of the construction of the

National Health Information Network (NHIN) National Health Information Network (NHIN)

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Who has an E.H.R.?Who has an E.H.R.?

http://www.aafp.org/fpm/2009/1100/10.html

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Now that Patient Information is at Now that Patient Information is at the bedside, why not solve the bedside, why not solve

questions there too?questions there too?

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1. Screening: 1. Screening: 56 year old male wants to know 56 year old male wants to know why there is a controversy about why there is a controversy about

Prostate Cancer screening; Prostate Cancer screening; “if “if you find it early, won’t I stand a you find it early, won’t I stand a better chance of living longer?”better chance of living longer?”

For Questions about SCREENING, For Questions about SCREENING, use:use:

www.ahrq.gov www.ahrq.gov

6060

Prevention: www.ahrq.govPrevention: www.ahrq.gov

6666

2. Basics:2. Basics:You have a MS III in your office who sees a You have a MS III in your office who sees a

patient w/ patient w/ Irritable Bowel SyndromeIrritable Bowel Syndrome & & wants to learn about this Diagnosiswants to learn about this Diagnosis

www.emedicine.com www.emedicine.com freefree www.epocrates.com free/$www.epocrates.com free/$ www.5mcc.com $www.5mcc.com $

NotNot: Google or Wikipedia: Google or Wikipedia

6767

OR, go to: www.emedicine.com

7070Epocrates: www.epocrates.com

7171

Continuing Med. Ed.Continuing Med. Ed.

““Listen to Lecture”Listen to Lecture”

+: “hit PLAY”+: “hit PLAY”

-: Industry Funded/Biased, Boring-: Industry Funded/Biased, Boring

Point of Care (tracks usage)Point of Care (tracks usage)

+: Fills YOUR Knowledge Gaps, +: Fills YOUR Knowledge Gaps, rewards your desire to improverewards your desire to improve

UpToDate, 5 Minute CC, DynamedUpToDate, 5 Minute CC, Dynamed

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3. Deeper Dive3. Deeper Dive 79 y/o becomes acutely ill after his 79 y/o becomes acutely ill after his

most recent intra-vesicle BCG most recent intra-vesicle BCG instillation for Transitional Cell Ca of instillation for Transitional Cell Ca of

Bladder; what should you do?Bladder; what should you do?

www.uptodate.com $www.uptodate.com $

www.accessmedicine.com www.accessmedicine.com (Harrison’s) $(Harrison’s) $

7474150 Hits

7575

4. Best Evidence4. Best Evidence

You are frustrated about the controversy You are frustrated about the controversy re: serum homocysteine levels in re: serum homocysteine levels in

patients at risk for CHD and you want patients at risk for CHD and you want the the

BEST EVIDENCEBEST EVIDENCE..

Systematic Review DatabasesSystematic Review Databases• Cochrane Database of Systematic ReviewsCochrane Database of Systematic Reviews• Others from PUBMED.GOVOthers from PUBMED.GOV

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What is What is Evidence Based Practice?Evidence Based Practice?

Integration ofIntegration of

• Best research evidenceBest research evidence

• Clinical expertiseClinical expertise

• Patient valuesPatient values

Most Explicit: Use a Systematic Review Most Explicit: Use a Systematic Review to guide Patient Careto guide Patient Care

Sacket et al “How to Teach and Practice EBM”, Churchill Livingston, 2000

www.pubmed.gov

www.pubmed.govwww.pubmed.gov

Use Clinical Queries FilterUse Clinical Queries Filter Search suffixesSearch suffixes * adds any suffix to the end of the * adds any suffix to the end of the

word (ie. asthm*)word (ie. asthm*) [ti] = any term in the title [ti] = any term in the title

(ie. Asthm*[ti])(ie. Asthm*[ti]) [ab] = any term in abstract[ab] = any term in abstract

(ie. Asthm*[ab](ie. Asthm*[ab]

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Online & Electronic ToolsOnline & Electronic ToolsCost/Yr Pros Cons

SCREENING:

www.ahrq.gov

$0.00 -Free

-Unbiased

-Standard of Care

- Too many “I” ratings

BASICS:

www.emedicine.com

$0.00 Free

-Current

-Lots of ads, now owned by Medscape

-May become biased based upon funders

-PDA version weak

BASICS::

www.epocrates.com

$195.00 -Rx, Basics, DDX, Lab, calculators, Pt Ed

-Not Biased

-PDA & Web

-Web not done yet

BASICS::

www.5mcc.com

$99.00 -Rx, Basics, DDX, Lab, Video, Calculators, Patient Education

-One fee Book, PDA, Web

-no CME yet

Deeper Dive

www.uptodate.com

$500-1st Yr

$400

-Comprehensive Medicine content

Subspecialist Author

-PDA, CME

-can be overwhelming

-PDA version HUGE

Deeper Dive www.accessmedicine.com/harrisons

$200/yr Adult Medicine -have to buy subscriptions to other resources, which adds up quickly

BEST EVIDENCE

www.pubmed.gov

Free Use Clinical Queries filter Not all reviews listed are systematic reviews, read carefully

Solving Questions on the Fly:Solving Questions on the Fly:Using Best EvidenceUsing Best Evidence


ProfessorProfessor

Dept. Family Medicine & Community HealthDept. Family Medicine & Community Health

University of Massachusetts Medical SchoolUniversity of Massachusetts Medical School

Worcester, MassachusettsWorcester, Massachusetts

[email protected]@umassmemorial.org

8484

Let’s look for answers to your Let’s look for answers to your questionsquestions

understanding concepts of evidenced based medicine

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