Evidence Based Evidence Based Obstetric MedicineObstetric Medicine

Robert Hopkins, MD, FACP, FAAPUAMS Associate Professor of

Medicine and Pediatrics

OutlineOutline

• EBM Overview– What is EBM– Why is EBM important– Basics of E-B medical practice

• Evidence Based Obstetrics 2005– Selected examples

• EBM Overview– What is EBM– Why is EBM important– Basics of E-B medical practice

• Evidence Based Obstetrics 2005– Selected examples

Overcoming inertia…Overcoming inertia…• “Human nature: apply minimum work in order to

complete the task at hand…”

• “We need to learn not only HOW to read the literature---but also WHAT to read and WHEN to read it…”

• “Usefulness = Validity * Relevance [of data] Work (required to find data)”

• “Human nature: apply minimum work in order to complete the task at hand…”

• “We need to learn not only HOW to read the literature---but also WHAT to read and WHEN to read it…”

• “Usefulness = Validity * Relevance [of data] Work (required to find data)”

What is EBM? [1]What is EBM? [1]• Patient centered• Ask answerable questions• Search for best evidence

– Can be time consuming… unless using E-B sources• Critical assessment of evidence

– For validity and applicability – May be time consuming, as above– If we do not assess critically, our educated

consumers/patients will go elsewhere…

• Patient centered• Ask answerable questions• Search for best evidence

– Can be time consuming… unless using E-B sources• Critical assessment of evidence

– For validity and applicability – May be time consuming, as above– If we do not assess critically, our educated

consumers/patients will go elsewhere…

What is EBM? [2]What is EBM? [2]• Evaluate applicability [of search results]

– Does the evidence apply to this patient?– Integrate evidence with clinical expertise– Is the intervention applicable to this specific person– ‘Guideline dilemma’: is this a replication of expert

(egocentric) opinion or a compendium of evidence…

• Critically assess the impact of change– To the patient– To the clinician – To ‘my medical practice’

• Evaluate applicability [of search results]– Does the evidence apply to this patient?– Integrate evidence with clinical expertise– Is the intervention applicable to this specific person– ‘Guideline dilemma’: is this a replication of expert

(egocentric) opinion or a compendium of evidence…

• Critically assess the impact of change– To the patient– To the clinician – To ‘my medical practice’

So… What is the problem?So… What is the problem?

Medical knowledge continues to grow• 3000 new papers published DAILY• 1000 new Medline article citations DAILY• 46 new RCT’s published DAILY

We do NOT read enough:• < ½ hour/week: 3 %• 1 hour/week: 46 %• 1-2 hr/week: 43%• 3+ hours/week: 8 %

Medical knowledge continues to grow• 3000 new papers published DAILY• 1000 new Medline article citations DAILY• 46 new RCT’s published DAILY

We do NOT read enough:• < ½ hour/week: 3 %• 1 hour/week: 46 %• 1-2 hr/week: 43%• 3+ hours/week: 8 %

BUT…Aren’t we doing OK???BUT…Aren’t we doing OK???• Data re: practice variability (200+ studies)

– [IM] Example: Determinants of need to Rx HTN• Level of BP• Patient age• Year MD awarded• End-organ damage

• Can we realistically expect to provide the best care for 100+ patients/wk relying on memory and experience alone???

• Data re: practice variability (200+ studies)– [IM] Example: Determinants of need to Rx HTN

• Level of BP• Patient age• Year MD awarded• End-organ damage

• Can we realistically expect to provide the best care for 100+ patients/wk relying on memory and experience alone???

Where does the data come from?Where does the data come from?

• Print source– Texts: General/Subspecialty/PDR– Journals– Reprints

• Human source– Consultations– CME Conferences– Pharmaceutical rep’s

• Other:– Electronic: Best Evidence CD, UpToDate, PIER,…– Paper: Clinical Evidence [Updates]– Specialty Societies

• Print source– Texts: General/Subspecialty/PDR– Journals– Reprints

• Human source– Consultations– CME Conferences– Pharmaceutical rep’s

• Other:– Electronic: Best Evidence CD, UpToDate, PIER,…– Paper: Clinical Evidence [Updates]– Specialty Societies

The CME ConundrumThe CME Conundrum

• CME is a ‘growth industry’

• Most presentations are ‘Fact’ oriented

• Several RCT’s have demonstrated no improvement in clinical performance…

Freemantle N., et.al. Cochrane Database of Systematic Reviews 2000;2.

• CME is a ‘growth industry’

• Most presentations are ‘Fact’ oriented

• Several RCT’s have demonstrated no improvement in clinical performance…

Freemantle N., et.al. Cochrane Database of Systematic Reviews 2000;2.

What are the answers?What are the answers?

• Seek out and apply evidence others generated• Learn how to practice EBM ourselves

Ultimate goal is …to apply evidence-centered strategies to answer questions in our practice-- leading to refinement of our clinical behavior.

• Seek out and apply evidence others generated• Learn how to practice EBM ourselves

Ultimate goal is …to apply evidence-centered strategies to answer questions in our practice-- leading to refinement of our clinical behavior.

What evidence do we need?What evidence do we need?

Evidence about:– Predictive values and likelihood ratios for

diagnostic tests– Power and specificity of prognostic markers– Comparative efficacy and safety of interventions

Evidence about:– Predictive values and likelihood ratios for

diagnostic tests– Power and specificity of prognostic markers– Comparative efficacy and safety of interventions

How often do we need EBM?How often do we need EBM?

Studies estimate at least: – 5 valid questions for every inpatient stay– 2 questions for every 3 outpatient visits

And yet– We get less than 1/3 of these answered…

Studies estimate at least: – 5 valid questions for every inpatient stay– 2 questions for every 3 outpatient visits

And yet– We get less than 1/3 of these answered…

To summarize- Why EBM?To summarize- Why EBM?• Too many patients• Too many questions• Too much information to glean all the PEARLS• No time to read• “Selection pressure” on the reading we do

– Reading often focused on familiar source/topic– It is common practice to avoid difficult issues and

focus on ‘quick answers’

• Too many patients• Too many questions• Too much information to glean all the PEARLS• No time to read• “Selection pressure” on the reading we do

– Reading often focused on familiar source/topic– It is common practice to avoid difficult issues and

focus on ‘quick answers’

What is the BEST evidence?What is the BEST evidence?1989 Georgia [One man’s opinion] • ‘Old Professors’• Case series• Systematic Review• Randomized Controlled• Meta-Analysis• Case Control • Colleague/Consultant• Case report

1989 Georgia [One man’s opinion] • ‘Old Professors’• Case series• Systematic Review• Randomized Controlled• Meta-Analysis• Case Control • Colleague/Consultant• Case report

Structuring the QuestionStructuring the Question

• Unstructured: Too many ‘hits’ – Example: >13000 [Pregnancy + HTN] articles

PubMed [1/15/05]

• Structuring questions– Background: W5s and How

• ‘W’ + Verb + Disease…

– Foreground: most daily ‘clinical care’ issues

• Unstructured: Too many ‘hits’ – Example: >13000 [Pregnancy + HTN] articles

PubMed [1/15/05]

• Structuring questions– Background: W5s and How

• ‘W’ + Verb + Disease…

– Foreground: most daily ‘clinical care’ issues

Background QuestionsBackground Questions

• Who, What, When, Where, Why, How..– + [verb] + [DISease]

• Results:– Often answered by textbooks, reviews– Most common when unfamiliar with a topic

• Who, What, When, Where, Why, How..– + [verb] + [DISease]

• Results:– Often answered by textbooks, reviews– Most common when unfamiliar with a topic

Foreground QuestionsForeground Questions

• Question Structure

– Patient or problem

– Intervention or exposure considered

– Comparison intervention (If relevant)

– Outcome of interest

• Question Structure

– Patient or problem

– Intervention or exposure considered

– Comparison intervention (If relevant)

– Outcome of interest

CQ ExampleCQ Example– In pregnant woman with severe HTN

[>170/100] is Labetalol as effective as Hydralazine in reduction of BP and maternal morbidity? • Result: Cochrane DB Systematic Reviews: 2003

[Other than Diazoxide [more symptomatic hypotension], there are no clear differences in studied agents including Labetalol, Hydralazine, Nifedipine ER,…]

– In pregnant woman with severe HTN [>170/100] is Labetalol as effective as Hydralazine in reduction of BP and maternal morbidity? • Result: Cochrane DB Systematic Reviews: 2003

[Other than Diazoxide [more symptomatic hypotension], there are no clear differences in studied agents including Labetalol, Hydralazine, Nifedipine ER,…]

Search for the EvidenceSearch for the EvidenceDatabase: Pub Med, Ovid and others

Search engines are highly sensitive…but they are not specific (Specificity left to the questioner/searcher)

MeSH: Structured medical subject headings- freely available from NLM (topic map) allow targeting of search to topic

‘Related articles’ is useful if narrow topic evaluated

Limits: Clinical Trial OR Systematic Reviews

English(?) languageHuman subjects

Database: Pub Med, Ovid and othersSearch engines are highly sensitive…but they are not specific

(Specificity left to the questioner/searcher)

MeSH: Structured medical subject headings- freely available from NLM (topic map) allow targeting of search to topic

‘Related articles’ is useful if narrow topic evaluated

Limits: Clinical Trial OR Systematic Reviews

English(?) languageHuman subjects

Evaluating the EvidenceEvaluating the EvidenceSome ‘pre-assessed’ sources for your use:

– ACP Journal Club, Journal of Evidence-Based Medicine– NGC: http://www.guideline.gov– Cochrane database– Clinical Evidence (BMJ Publications)– UpToDate

JAMA Guide: EBM Working Group– Are the results valid?– What are the results?– Will the results help in my patients’ care?– http://medicine.ucsf.edu/resources/guidelines/users.html

Some ‘pre-assessed’ sources for your use:– ACP Journal Club, Journal of Evidence-Based Medicine– NGC: http://www.guideline.gov– Cochrane database– Clinical Evidence (BMJ Publications)– UpToDate

JAMA Guide: EBM Working Group– Are the results valid?– What are the results?– Will the results help in my patients’ care?– http://medicine.ucsf.edu/resources/guidelines/users.html

Data vs. Availability vs. UtilityData vs. Availability vs. UtilityData Source Access

QualityExperience Longitudinal Rapid VariableColleague Variable Variable VariablePatients Rapid Rapid ???Guidelines Variable Variable VariableTexts Rapid Slow Good?Research Slow Slow Good?Journals Buried Variable Good

Data Source Access Quality

Experience Longitudinal Rapid VariableColleague Variable Variable VariablePatients Rapid Rapid ???Guidelines Variable Variable VariableTexts Rapid Slow Good?Research Slow Slow Good?Journals Buried Variable Good

Who are we??Who are we??

• Evidence Users• Evidence Finders• Evidence Generators

[And I hope Never…]• Evidence Ignorers

• Evidence Users• Evidence Finders• Evidence Generators

[And I hope Never…]• Evidence Ignorers

What is our goal in EBM?What is our goal in EBM?To NOT have to wade through 100+ papersTo NOT have to go through MedlineTO have evidence indexed by strengthTO have a brief (1 word ?) answer…TO see questions that are already answered

i.e. ALL applicable knowledge in 15 seconds…FLAT….

To NOT have to wade through 100+ papersTo NOT have to go through MedlineTO have evidence indexed by strengthTO have a brief (1 word ?) answer…TO see questions that are already answered

i.e. ALL applicable knowledge in 15 seconds…FLAT….

Evidence Based OB 2005Evidence Based OB 2005

13043 “Pregnancy + HTN” articles

[Pubmed 1/18/05]

• 207 when limited to Clinical trial, Human subjects, English language

13043 “Pregnancy + HTN” articles

[Pubmed 1/18/05]

• 207 when limited to Clinical trial, Human subjects, English language

Evidence Based OB 2005Evidence Based OB 2005

15852 “Preeclampsia” articles in 2005 [Pubmed 1/13/05]

– 263 articles when limited to: adults, human, English, published within 1 year

– 170 articles with MeSH ‘major topic’ limit– 15 Clinical trials [Publication type]– 7 Randomized Controlled Trials

15852 “Preeclampsia” articles in 2005 [Pubmed 1/13/05]

– 263 articles when limited to: adults, human, English, published within 1 year

– 170 articles with MeSH ‘major topic’ limit– 15 Clinical trials [Publication type]– 7 Randomized Controlled Trials