Evidence-Based Medicine in PubMed

PubMed for Trainers, Winter 2015U.S. National Library of Medicine (NLM) and NLM Training Center

Objectives

To explore MeSH vocabulary and PubMed features that facilitate finding evidence-based researchDefine the term “evidence based medicine”Identify and discuss publication types and research design

vocabulary available in MeSHIntroduce and examine three PubMed topic-specific searches:

clinical queries; systematic reviews; and comparative effectiveness research

Introduce PubMed Health

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What is Evidence-Based Medicine?

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“integrating individual clinical expertise with the best available external clinical evidence from systematic research”

See Sackett, D. Evidence-based Medicine - What it is and what it isn't. BMJ 1996; 312:71-72. http://www.bmj.com/cgi/content/full/312/7023/71

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The Evidence Pyramid

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“The best evidence is usually found in clinically relevant research that has been conducted using sound methodology.” (Sackett D, 2002)

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What do we mean by “Evidence-Based Medicine” in the context of PubMed?

Identifying the best available evidence in the literature to inform clinical decision making using MeSH vocabulary and PubMed features.

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Evidence-Based Medicine

MeSH Vocabulary

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Useful MeSH terms used to

describe research design

and methodology

Study Characteristics

(PTs)

Investigative Techniques

(MHs)

Publication Types

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Describe the item being indexed rather than its topic.  

There are 3 main categories: Publication Components, e.g., English AbstractPublication Formats, e.g., Lectures, LetterStudy Characteristics, e.g., Clinical Trial, Twin

Study

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Study Characteristics (PTs)

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Case Reports

Clinical Conference

Clinical Trial +

Comparative Study

Consensus Development Conference +

Evaluation Studies

In Vitro

Meta-Analysis

Multicenter Study

Scientific Integrity Review

Twin Study

Validation Studies

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Study Characteristics (PTs)Clinical Trial

Clinical Trial, Phase IClinical Trial, Phase IIClinical Trial, Phase IIIClinical Trial, Phase IVControlled Clinical TrialMulticenter StudyObservational StudyRandomized Controlled Trial

Pragmatic Clinical Trial

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Clinical Trial Phases

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Phase I Is it safe?

Phase II What’s the right dose?

Phase III How good is it compared to the standard treatment?

Phase IV Does it have any rare or long term adverse effects?

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Publication Type vs. Method “as Topic”

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Research Design MeSH Headings:Investigative Techniques (examples)

Double-blind method (1990, Aug 1977)Cohort Studies (1989)Matched-Pair Analysis (1992)Patient selection (1995)Random allocation (1991, 1978)

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http://www.ncbi.nlm.nih.gov/mesh?term=Investigative%20Techniques

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MeSH Pop Quiz!

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Exercise

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Construct a PubMed search strategy to find studies comparing treatments for sleep apnea.

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HINT: You’re looking for a PT.

Evidence-Based Medicine

PubMed Tools

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Clinical Queries

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Clinical Queries: Clinical Study Categories

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Clinical Queries: Clinical Study Categories

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Systematic Reviews Defined (by NLM)

1. One or more questions are posed.

2. Studies’ results are collected.

3. Criteria are used to include or exclude studies.

4. Data extracted from the selected studies are combined and compared.

5. Conclusions are made.

http://www.nlm.nih.gov/pubs/techbull/jf02/jf02_systematic_reviews.html

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PubMed Systematic Review query also includes:

meta-analysesreviews of clinical trialsevidence-based medicineconsensus development conferencesguidelines, and citations to articles from journals specializing in

clinical review studies.

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Filter strategy: http://www.nlm.nih.gov/bsd/pubmed_subsets/sysreviews_strategy.html Revised February

2015

Exercise: Clinical Queries

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Using the Clinical Queries page, find studies exploring the effect of weight loss on obstructive sleep apnea

Look at the Systematic Reviews and click See all to view them in PubMed

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Comparative Effectiveness

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effectiveness [sb]

http://www.nlm.nih.gov/nichsr/cer/cerqueries.html Revised February 2015

RCTs

PubMed CER Searches Conceptual Structure

Outcomes

ALL of the Above

Systematic Reviews

CohortAdministrative

Data/Registries/EHRs

Health Disparities

Simulations Modeling

Comparative OR

Effective

Costs & Cost Analysis

Outcomes

“About” CERANDOR

Clinical Studies

Observational Studies

Systematic Reviews

Comparative OR

Effective

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http://www.nlm.nih.gov/nichsr/cer/CER_search_strategies.html

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Exercise: Comparative Effectiveness Research

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Use the comparative effectiveness search page to search for weight loss on obstructive sleep apneaLook at results for Observational StudiesLook at results for Systematic Reviews, Simulations,

ModelsCompare your results for CER search on

Systematic Reviews with the Clinical Queries Systematic Reviews search results

http://www.nlm.nih.gov/nichsr/cer/cerqueries.html

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Full-text online collection of systematic reviews (or summaries)

CuratedSome not in PubMed

http://www.ncbi.nlm.nih.gov/pubmedhealth/

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Another EBM Resource:

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Your Turn

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Which is the better way of diagnosing kidney stones in the emergency room, ultrasound or CT scan?

Your Turn

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What is the efficacy of prophylactic mastectomy?

Your Turn

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What are the best strategies for treating high blood pressure in African Americans?

Your Turn

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What would be the better treatment for patients over 80 who need hip surgery? The sliding hip screw or intramedullary nail? How long is their recovery and quality of life differential between both procedures?

Evidence-Based Medicine

My NCBI Tricks and Tips

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My NCBI Tip: Filters

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My NCBI Tip: Custom Filters

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My NCBI Tip: Custom Filters

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More about Comparative Effectiveness Research

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Webinar: Comparative Effectiveness Research (from the Pacific Northwest RML): https://webmeeting.nih.gov/p77505591/

Finding Evidence for Comparing Medical Interventions (AHRQ Guide on comparative effectiveness reviews)http://www.ncbi.nlm.nih.gov/pubmed/21433408

Systematic Review Workshop: The Nuts and Bolts for Librarians (3-day workshop)http://www.hsls.pitt.edu/systematicreview/

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More about Evidence-Based Medicine

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Online tutorial: http://guides.mclibrary.duke.edu/ebmtutorial

Work by Dr. John Ioannidis (see profile in the Atlantic http://www.theatlantic.com/magazine/archive/2010/11/lies-damned-lies-and-medical-science/8269/ and/or search PubMed for ioannidis jp)

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Summary

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VocabularyStudy Characteristics (PTs)Investigative Techniques headings

PubMed Clinical and Special QueriesClinical Study Categories (Clinical Queries page)Systematic Reviews (Clinical Queries page)Comparative Effectiveness (NICHSR Web site)

PubMed Health for full-text systematic reviews

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