evidence based practice lecture sandra a. martin, m.l.i.s. health sciences resource coordinator...
TRANSCRIPT
Evidence Based Practice Lecture
Sandra A. Martin, M.L.I.S.Health Sciences Resource Coordinator
Instructor of Library ServicesJohn Vaughan Library Room 305B
[email protected] – 918-444-3263
Existing knowledge can prevent…
•Waste•Errors•Poor quality clinical care•Poor patient experience•Adoption of interventions of low value•Failure to adopt interventions of high value
Source: Sir Muir Gray, Chief Knowledge Officer of Britain’s National Health Service. Quoted on http://www.nks.nhs.uk/.
Harmful practices once supported by expert opinion
Source: Adapted from How to read a paper: the basics of evidence-based medicine. 4 th edition. By Trisha Greenhalgh. 2010 Blackwell Publishing
Time period Accepted practice Shown to be harmful
Impact on clinical practice
From 500 bc Blood Letting 1820 Ceased in 1910
1957 Thalidomide for morning sickness in early pregnancy
1960 Withdrawn when first case report of severe malformations appeared
From 1900 Bed rest for acute low back pain
1986 Still advised by some doctors
1960s Benzodiazepines for mild anxiety
1975 “Diazepam” prescribing fell in 1990s due to severe dependence and withdrawal symptoms
Late 1990s Cox-2 inhibitors to treat arthritis
2004 Withdrawn following legal cases in the US
Information Retrieval for Evidence Based Patient Care Using research findings versus conducting research Retrieving and evaluating information that has direct
application to specific patient care problems Selecting resources that are current, valid and available
at point-of-care Developing search strategies that are feasible within
time constraints of clinical practice
Learning Objectives
At the end of the presentation, you will be able to:• Define evidence-based medicine (EBM)• Understand the Five Steps to practice EBM• Use the 4S hierarchy to conduct an efficient search for
the best evidence• Access online pre-appraised resources• Locate print and online tools to assist in critical
appraisal of individual studies• Practice the Five Steps in clinical settings
www.cebm.net
“Evidence-based medicine is the integration of best research evidence with clinical expertise and patient values”
Sackett DL, Rosenberg WMC, Gray JAM, Haynes RB, Richardson WS: Evidence based medicine: what it is and what it isn’t. BMJ 1996;312:71-2.
Patient Concerns
Clinical Expertise
Best research evidence
EBM
What is EBM?
Evolution of EBM in the Literature
Term first appeared in the literature in a 1991 editorial in ACP Journal Club Volume 114, Mar-April 1991, pp A-16
Seminal article by the Evidence-Based Medicine Working Group published in JAMA Volume 268, No. 17, 1992, pp 2420-2425
Fundamentally new approach becomes widely recognized JAMA published a series of Users’ Guides to the Medical
Literature that served as the first learning tools Courses were developed in residency training and
medical school curricula The first handbook, Evidence-Based Medicine: How to
practice and teach EBM, by Sackett, et al, was published in 1996. Fourth edition published in 2010.
New York Times listed EBM as one of its ideas of the year in 2001
BMJ listed EBM as one of the 15 greatest medical milestones since 1840
Integration of EBM into medical school curricula patient-doctor courses
EBM Process – 5 Steps
1. ASK: Convert need for information into answerable question
2. ACQUIRE: Find best evidence to answer the question
3. APPRAISE: Critically appraise evidence for validity, impact, and applicability
4. APPLY: Integrate evidence with clinical expertise and patient values
5. ASSESS: Evaluate own effectiveness
New Approach Requires New Skills
Clinical question formulation Search and retrieval of best evidence Critical appraisal of study methods to determine validity
of results
Background v Foreground Knowledge
Both types of knowledge needed Varies over time Depends on experience with condition Point A: Student – limited experience Point B: Resident – growing clinical experience Point C: Attending – extensive experience Note: Diagonal line shows “we’re never too green to
learn foreground knowledge, nor too experienced to outlive the need for background knowledge”
Source: Evidence-based medicine: how to practice and teach it. 4 th edition. By Straus, et. al. Churchill Livingstone Elsevier
Answerable Questions
Arise in patient care setting and are: Important to the patient’s well being Fill gaps in your clinical knowledge Feasible to answer in time available
Clinical Questions
Four Common Types Therapy/prevention Diagnosis Etiology Prognosis
Therapy Question Example
In patients with primary open angle glaucoma, [Patient/Population], do topical medications to reduce intraocular pressure [Intervention] versus no treatment [Comparison Intervention], delay visual field defect progression [Outcome]?
PICO Model
P - Patient or population
I - Intervention
C - Comparison Intervention
O - Outcome
Possible Search Terms
Primary open angle glaucoma, POAG, topical medications, intraocular pressure, IOP, visual fields, VF
Evidence Based Retrieval
1. Find the answer that is supported by valid studies appropriate to the type of question and that is available in a timely manner.
2. Requires search terms plus best study design for question plus highest level of evidence
Best Study Design for Type of Question
Type of Question Study Design
Therapy/prevention Randomized controlled trials
Diagnosis Prospective cohort, blind comparison to a gold standard
Prognosis Cohort, Case Control, Case Series
Etiology/Harm Cohort, Case Control, Case Series
Is All Evidence Created Equal?
Small portion of medical literature is immediately useful to answer clinical questions
Understanding “wedge or pyramid of evidence” is helpful in finding highest level of evidence
High levels of evidence may not exist for all questions due to nature of medical problems and research limitations
As you move up the pyramid the amount of available literature decreases, but it increases in its relevance to the clinical setting.
Source: Sackett, D.L., Richardson, W.S., Rosenberg, W.M.C., & Haynes, R.B. (1996). Evidence-Based Medicine: How to practice and teach EBM. London: Churchill-Livingstone.
Levels of Evidence
Grade the quality of evidence based on the design of the clinical study
Variety of hierarchies in use
Hierarchy of Published Evidence for Intervention StudiesLevel of Evidence Description Study Example
1 Randomized clinical trial with low study errors or a meta-analysis
Optic neuritis treatment trial N Engl J Med. 1992; 326:581-588
2 Randomized clinical trial with high study errors
Scatter laser photocoagulation for occult choroidal neovascularization Arch Ophthalmol. 1996; 114:1456-1464
3 Clinical trial with a control group, with nonrandom treatment allocation
Thrombolytic therapy for acute retinal arterial occlusion Am J Ophthalmol. 1992; 113:429-434
4 Intervention case series Macular translocation surgery for the treatment of CNVM and AMD Am J Ophthalmol. 1968; 66:597-603
5 Interventional case report Removal of a choroidal neovascular membrane Retina. 1994; 14:125-129
American Academy of Family Physicians SORT – used in OVID MEDLINE Clinical Queries Limit Level A
Systematic reviews of randomized controlled trials including meta-analyses
Good-quality randomized controlled trials Level B
Good-quality nonrandomized clinical trials Systematic reviews not in Level A Lower-quality randomized controlled trials not in Level A Other types of study: case control studies, clinical cohort studies,
cross sectional studies, retrospective studies, and uncontrolled studies
Level C Evidence-based consensus statements and expert guidelines
GRADE SystemUptoDate, First Consult
Key developments that streamlined the practice of EBM Advances in ease of accessing and understanding
information Development of preprocessed (preappraised) tools Improvements in search interfaces to MEDLINE Collaboration between EBM Working Group and
National Library of Medicine in development of hedges, “clinical queries” tool, that filters search results to specific study types and levels of evidence
Dissemination of systematic reviews of primary studies and growth of the Cochrane Collaboration
4S Hierarchy
Highest Level of Evidence - Critically Appraised Content
Evidence Based Summaries: UpToDate, First Consult,
ACP Journal Club, DARE
Cochrane Database of Systematic Reviews
Clinical Key & Ovid MEDLINE limited to Study Types and Clinical Queries
SOURCE: Haynes, R. B. (2001). Of studies, syntheses, synopses, and systems: the “4S” evolution of services for finding current best evidence. Evidence-Based Medicine, 6 (2), 36-38. Retrieved 2-07-07 from http://ebm.bmj.com/cgi/reprint/6/2/36
Summaries• UptoDate
– Evidence based summaries of over 9,500 topics in over 22 specialties
– 8,500 Graded Treatment Recommendations– Drug Database with tools and calculators– Patient Education materials– Practice Changing Updates; Updated
continuously– The Gold Standard of evidence based
summaries
UTD
Therapy Question Example
In patients with primary open angle glaucoma, [Patient/Population], do topical medications to reduce intraocular pressure [Intervention] versus no treatment [Comparison Intervention], delay visual field defect progression [Outcome]?
UpToDate Summary
GRADE SystemUptoDate, First Consult
Therapy Discussion
1:54
Evidence-based Reference
Clinical Key
Full text access to 1,000 books and 500 journals in every medical and surgical specialty
Ophthalmology – Over 60 full text books Includes 12 Content Types Access to information at all levels from topic overview to
evidence-based data in one search Smart search engine matches first few letters of search
word/words to relevant clinical content No complicated search strategies or Boolean connectors Easier than Google – but with reliable, evidence-based
results
Summaries• First Consult CK Online & App
– Available through NSU subscription to Clinical Key for iPhone or iPad only
– Create a personal account in Clinical Key Online
– Download the app from the Apple app store– Login with your Clinical Key username and
password– Summaries are detailed and include sections
on Differential Diagnosis
Syntheses
• Cochrane Database of Systematic Reviews (DSR)– Part of the Cochrane Library (1996)– Over 900 completed reviews, 1900 protocols– Among the highest level of evidence upon
which to base treatment decisions– Includes Dx since 2008– Eyes & Vision Research Group
• Contains over 200 reviews
Systematic Review
Analyzes data from several primary studies to answer a specific clinical question
Provides search strategies and resources used to locate studies
Includes specific inclusion and exclusion criteria (results in less bias)
Meta-Analysis (subclass) statistically summarizes results of several individual studies
Access full text of Cochrane reviews in OVID
Review found in 15 seconds
Cochrane DSR
Copyright: The Cochrane Library, Copyright 2009, The Cochrane Collaboration
Appraisal Required by User
Primary (Original) Studies
Articles that report results of original research investigations
Conclusions supported by data and reproducible methodology
Require time to acquire and appraise Good Sources: Ovid MEDLINE and
Clinical Key
When to search for original studies If the other “S’s” don’t provide the answer,
search for original studies “Do it yourself” appraisal territory You must appraise quality of the study or
find analysis in evidence based summary Limit to “Study Type” in Clinical Key or
“Clinical Queries” in Ovid MEDLINE
Databases
• MEDLINE– Premiere biomedical database from the NLM
(National Library of Medicine)– Covers 1946-present– Indexes >5000 international biomedical
journals– Full text available for many articles– Access through Ovid and Clinical Key
MEDLINE Search Limits
• Limit search results to study type– Randomized controlled trials– Clinical trials
• In OVID, limit by “Clinical Queries” • Appraise study for validity and relevance
Ovid MEDLINE Clinical Queries
Levels of Evidence in Ovid based on AAFP SORT
Level A = “Specificity” in Ovid Clinical Queries Systematic reviews of randomized controlled trials including meta-
analyses Good-quality randomized controlled trials
Level B = “Sensitivity” in Ovid Clinical Queries Good-quality nonrandomized clinical trials Systematic reviews not in Level A Lower-quality randomized controlled trials not in Level A Other types of study: case control studies, clinical cohort studies,
cross sectional studies, retrospective studies, and uncontrolled studies
Level C Evidence-based consensus statements and expert guidelines
Take Home Points
Focused clinical question (PICO) reveals your search terms
Start your search at top of 4S hierarchy and work down (UpToDate, First Consult)
Be aware of the filter, i.e., levels of evidence, speed of updating
Look at more than one resource in the hierarchy. Findings may differ
Apply in clinical settings; Assess your progress
