Session Slides

FINDING THE BEST EVIDENCE: AN OVERVIEW OF THE RESOURCESSPRING 2010

“…conscientious, explicit and judicious use of the current best evidence in making decisions about the care of individual patients…” -- Sackett, DL

THIS SESSION WILL COVER

What do we mean by evidence-based health care Steps in practicing evidence-based care Types of literature Key resources for finding evidence-based

information

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Clinically relevant research, the literature

Practitioner’s knowledge& experience

Patient’s characteristics & values

THREE PRONGED APPROACH

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Need for current clinical information Updates info in textbooks, journals, experts Skills/experiences increase over time, current

knowledge may decrease Increase in clinical research and literature Conflicting clinical research [at times] Limited time to find and evaluate research

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WHY USE AN EVIDENCE-BASED APPROACH?

1. Convert need for information into focused clinical question

2. Track down the best evidence3. Critically appraise the evidence4. Integrate evidence with clinical expertise and

patient values5. Evaluate the process and adjust as needed

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STEPS IN PRACTICING EBP

Evidence-based Medicine:How to Practice and Teach EBMBy Straus SE, et alThird Edition.Churchill Livingstone: Edinburgh, 20050-443-07444-5, 299 pages. Includes CD-ROM

Your patient is a 14-yr old boy with a weight

problem (obesity). He has tried lifestyle changes and they have not been

effective, so he and his parents ask you about other weight loss options for an adolescent.

Pho

to f

rom

CD

C: C

hild

hoo

d o

verw

eig

ht

CLINICAL SCENARIO

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Background vs. Foreground questions

Background questions – getting up to speed on a topic.General knowledge about a disorder. Look for info in textbooks, summary material.

Foreground questions – specific knowledge about managing a patient or disorder. Apply EBP techniques, use EBP resources

USING THE LITERATURE IN PRACTICE

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UpToDate Clinical Evidence MDConsult STAT!Ref MICROMEDEX Specialty texts via Ebling Library

websiteHarrisons

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BACKGROUND SOURCES

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Medical topics in internal medicine (particularly strong), pediatrics, ob/gyn and family medicine

Designed to provide a quick way to get up to speed An updated version of UpToDate is released every four

months “What’s New” tab highlight changes with each major release.

For use in EBM is a mixed bag (use cautiously to answer clinical questions (i.e. PICO questions)

Articles are a mixture of medical conclusions based on data from studies and expert opinions of individual authors…not always clear which statements are evidence-based and which are not

EVIDENCE-BASED CLINICAL SUMMARY

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Background vs. Foreground questions

Background questions – general knowledge about a disorder. Look for info in Reference sources

Foreground questions – specific knowledge about managing a patient or disorder. Apply EBP techniques, use EBP resources

In a 14 year old obese male, how effective is the drug Meridia for long term weight loss?

USING THE LITERATURE IN PRACTICE

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P I C O helps to formulate the question

Patient/Population/Problem

Intervention

Comparison

Outcome

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CONVERT THE CLINICAL QUESTION TO PICO

In a 14 year old obese male,how effective is the drug Meridia for long term weight loss?

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PI

O

C – no comparison/placebo

CONVERT THE CLINICAL QUESTION TO PICO

P = In a 14 yo obese maleI = is Meridia C = O = effective and safe for long term weight loss?

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P

obeseobesityoverweight

I

Meridia

sibutramine

CREATING A SEARCH QUERY

adolescentadolescenceteenteenageryouth

P = In a 14 yo obese maleI = is Meridia

14

Pobese

obesityoverweight

IMeridiasibutramine


adolescentadolescenceteenteenageryouth ORANGE = MeSH term

adolescent adolescence teen teenager youth child

obese obesity overweight

meridia sibutramine

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Place an “OR” between synonyms of the same concept and surround concept terms with parentheses

Place an “AND” between concepts

( OR OR OR OR OR )

( OR OR )

( OR )

AND

AND


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(adolescent OR adolescence OR teen OR teenager OR youth OR child) AND (obesity OR obese OR overweight) AND (meridia OR sibutramine)

(adolescen* OR teen* OR youth OR child) AND (obes* OR overweight) AND (meridia OR sibutramine)

Use truncation character, if available:


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1. Convert need for information into focused clinical question

2. Track down the best evidence3. Critically appraise the evidence4. Integrate evidence with clinical expertise and

patient values5. Evaluate the process and adjust as needed

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Clinical summariesMeta analyses/Systematic reviews

Randomized control trials (RCTs)Prospective cohort studiesCase-control (retrospective cohort) studiesCase studiesOpinion of authorities, editorials

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Level of

Evid

ence

low

high

EVIDENCE HIERARCHY

A compendium of short summaries of the current state of the knowledge (and uncertainty) about clinical conditions (prevention, treatment, and/or diagnosis)

Entries are explicitly based on thorough searches and appraisals of the literature and created from the best available evidence from systematic reviews, RCTs and observational studies


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Examples:

BMJ Clinical Evidence http://clinicalevidence.bmj.com/

Essential Evidence Plushttp://www.essentialevidence.com/

UpToDate http://www.uptodate.com

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EVIDENCE-BASED CLINICAL SUMMARIES

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Collection of brief reviews focusing on primary care and covering over 3,000 clinical interventions with 570 clinical questions answered.

Looks at current state of knowledge & ignorance about prevention and treatment. Describes the best available evidence and if there is no good evidence, it says so.

Each review focuses on single condition and is displayed in a tabbed structure:

• Single page summary of the review• Ranked list of interventions with discussion

(benefits/harms)• Background info on the condition• A list of material published since the review search

date• Links to major guidelines relevant to the review




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Level of

Evid

ence

low

high

EVIDENCE HIERARCHY

Summarize a particular topic by using explicit methods to perform a thorough literature search and critical appraisal of individual studies to identify the valid and applicable evidence

Uses appropriate techniques to combine these valid studies

Published in many journals and found in a variety of other electronic sources

SYSTEMATIC REVIEWS

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Examples:

Cochrane Database of Systematic Reviewshttp://www.cochrane.org/

DAREhttp://www.crd.york.ac.uk/crdweb/

TRIP Databasehttp://www.tripdatabase.com

MEDLINE (PubMed)http://www.pubmed.gov

SYSTEMATIC REVIEWS

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5,600 systematic reviews and meta-analyses Rigorous, highly-regarded, reviews Focused on therapy/prevention, now covering diagnostic

tests Database includes protocols -- plans or sets of steps to be

followed in creating a systematic review When searching within the Cochrane Library:

use the “Title, Abstract, Keywords” drop down to reduce irrelevant records

Contains 15,000 reviews of systematic reviews. Complements the CDSR -- quality-assesses and summarizes

reviews that have not yet been carried out by Cochrane When searching within the Cochrane Library:

use the “The full review (Search All Text)” drop down to reduce irrelevant records

SYSTEMATIC REVIEWS

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Often overlooked secondary source for evidence on any type of foreground question

Reviews the best original and review articles from over 100 of the top clinical journals

If included, it is important! Unlike DARE, clinical experts provide commentaries on the

context, methods, and clinical applications of the findings of each article

SYSTEMATIC REVIEWS

New interface Includes only records/abstracts of journal articles (20

million) Very current info (sometimes pre-pub) Use MeSH terms for more efficient searching Use Boolean operators (AND, OR) Searching for systematic reviews:

• Use the “Find Systematic Reviews” box in Clinical Queries OR Apply the Subsets limit “Systematic Reviews”

1990 1995 2000 2005

2500

12,500

5000

10,000

7500

# pu

blis

hed

per

year

15,000

2010

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SYSTEMATIC REVIEWS

2828

Many conditions, interventions, diagnostic tools without good SRs

Need constant maintenance. Half will need to be updated each year

Garbage in; garbage out FAAT handout http://www.cebm.net/index.aspx?o=1157

SYSTEMATIC REVIEWS



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Level of

Evid

ence

low

high

EVIDENCE HIERARCHYS

tud

ies

Examples:

MEDLINE (PubMed)http://www.pubmed.gov

Google Scholarhttp://scholar.google.com

Other health databases

CINAHL http://www.cinahl.com/

PsycINFO http://www.apa.org/psycinfo/

INDIVIDUAL STUDIES

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Includes only records/abstracts of journal articles (20 million)

Very current info (sometimes pre-pub) Use MeSH terms for more efficient searching Use Boolean operators (AND, OR) Searching for single studies:

• Use the “Search by Clinical Study Category” box in CQ• OR use the type of article limit: randomized controlled

trials or other appropriate level

Subset of larger Google: journal articles, technical reports, preprints, theses, books and other documents and web pages deemed “scholarly”

Covers a great range of disciplines (strong in sciences and medicine)

It is particularly helpful for users who want:• something good enough for the task at hand (not

comprehensive)• grey literature--sources outside of published journals• info from sources across many disciplines

Limitations: rudimentary search features, lack of transparency of database content, uneven coverage (time and scope) and a delay in indexing

INDIVIDUAL STUDIES

Identify synonyms Check MeSH database via PubMed Use generic and trade names for drugs and tests Use full names along with common abbreviations

OR between synonyms OR between synonyms Surround OR terms with parentheses

Enter concepts as separate sets AND between P,

I,C

common cold AND (vitamin c OR ascorbic acid)

GENERAL SEARCH HINTS

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1. Converting need for information into focused clinical question

2. Tracking down the best evidence3. Critically appraising the evidence4. Integrating evidence with clinical expertise

and patient values5. Evaluating the process


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Centre for EBM (Toronto)http://www.cebm.utoronto.ca

Centre for EBM (Oxford)http://www.cebm.net

Users’ Guides series in JAMAhttp://www.userguides.org

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CRITICALLY APPRAISING THE EVIDENCE

Statistics Toolkit

By Perera R, et alBMJ Books2008ISBN: 978-1-4051-6142-8120 pages

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1. Converting need for information into focused clinical question

2. Tracking down the best evidence3. Critically appraising the evidence4. Integrating evidence with clinical expertise

and patient values5. Evaluating the process


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Documents

Session Slides