The Culture of Healthcare Evidence-Based Practice Lecture b This material (Comp2_Unit5b) was developed by Oregon Health and Science University, funded.

The Culture of Healthcare

Evidence-Based Practice

Lecture b

This material (Comp2_Unit5b) was developed by Oregon Health and Science University, funded by the Department of Health and Human Services, Office of the National Coordinator for Health Information

Technology under Award Number IU24OC000015.

Evidence-Based PracticeObjectives

• Define the key tenets of evidence-based medicine (EBM) and its role in the culture of health care (Lectures a, b)

• Construct answerable clinical questions and critically appraise evidence answering them (Lecture b)

• Apply EBM for intervention studies, including the phrasing of answerable questions, finding evidence to answer them, and applying them to given clinical situations (Lecture c)

• Understand EBM applied to the other key clinical questions of diagnosis, harm, and prognosis (Lectures d, e)

• Discuss the benefits and limitations to summarizing evidence (Lecture f)

• Describe how to implement EBM in clinical settings through clinical practice guidelines and decision analysis (Lecture g)

2Health IT Workforce Curriculum Version 3.0/Spring 2012

The Culture of Healthcare Evidence-Based Practice

Lecture b

Making Evidence-Based Clinical Decisions (Mulrow, 1997)

5.1 Figure: Adapted from (Mulrow, Cook, & Davidoff ,1997)



Lecture b

Best Resources For EBM

• Three major books:– Straus et al., Evidence-Based Medicine: How to

Practice and Teach EBM, Third Edition, 2005• Formerly known as “the Sackett book”

– Guyatt et al., Users’ Guides to the Medical Literature, 2008 (two books – one a handbook, the other more complete)

• Web sites– http://www.cebm.net– http://www.cche.net/– http://ktclearinghouse.ca/cebm/– http://www.nettingtheevidence.org.uk/



Lecture b

http://www.cebm.net/

http://www.cche.net/

http://ktclearinghouse.ca/cebm/

The Changing Nature Of EBM (Hersh, 1999)

• Initial approach (aka, “first generation”) was for clinician to find and critically appraise evidence– Takes too much time, clinicians lack expertise

• More recent approach (aka, “next generation”) is synthesis and synopsis of evidence for clinician– Access to on-line, up-to-date information makes easier

• Slawson & Shaughnessy (2005) argue there should be more emphasis on teaching information management (seeking) than the techniques of EBM



Lecture b

Another Viewpoint Concerning Evidence (Haynes, 1999)

• Can it work?– Efficacy studies take place under “ideal” circumstances– This unit looks mainly at such studies

• Does it work?– Effectiveness studies ascertain whether something works in the

“real world”– Sometimes called “outcomes research” (Clancy & Eisenberg,

1998)• Is it worth it?

– Cost-benefit or cost-effectiveness studies determine whether benefits worthwhile in relation to cost or other resources



Lecture b

Hierarchy of Evidence – The “4S” Model (Haynes, 2001)

Subsequently updated to “5S”

(Haynes, 2005) and “6S”

models (DiCenso, 2009),

but this one is preferred

5.2 Figure: adapted from Hayne’s “4S” model of the Hierarchy of Evidence (2001)

Health IT Workforce Curriculum Version 3.0/Spring 2012


Lecture b7

Where The Evidence Comes From

5.3 Figure: Adapted from Haynes “S4” model of the Hierarchy of Evidence (2001) with types and sources of evidence



Lecture b

Studies

• Accessed (usually) in literature databases such as MEDLINE– Most common and freely available system for

accessing medical literature is Pubmed, available at http://pubmed.gov/

• Retrieved from journals– Many available electronically now

• Application of critical appraisal and formulae– e.g., relative risk, number needed to treat,

sensitivity, odds ratio, etc.



Lecture b

Syntheses

• Systematic reviews– Exhaustive review of data on a topic done in a

systematic manner• Not a simple literature review or overview of papers one

knows about– Application, where appropriate, of meta-analysis,

the combination of results from multiple studies in a single analysis

• Studies must be appropriately similar, and there are methodological means to assess that

– Available in Pubmed or in specialized Pubmed Health

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



Lecture b

Synopses And Systems

• Synopses – highly summarized information appropriate for clinical setting, e.g.,– Critically appraised topics (CATs)– Clinical Evidence, InfoPOEMS, PIER– Clinical practice guidelines

• Systems – decision support within electronic health records– Best way to provide evidence to clinicians at point of

decision-making



Lecture b

Overview Of The ApplicationOf EBM

• Steps include– Phrasing a clinical question that is pertinent

and answerable– Identifying evidence to address the question– Critically appraising the evidence to determine

if it applies to the patient



Lecture b

Phrasing The Clinical Question

• Background vs. foreground questions

– Background questions ask for general knowledge about a disorder• Usually answered with textbooks and

classical review articles

– Foreground questions ask for knowledge about managing patients with a disorder• Usually answered using EBM techniques



Lecture b

Background Questions

• General information not specific to a given patient

• Examples– What causes pneumonia?– When do complications of diabetes usually

occur?

• Distinction from foreground questions can be blurry– New etiologies of disease– Level of training, e.g., specialist vs. student



Lecture b

Foreground Questions• Have three or four essential components

(PICO)– Patient and/or problem– Intervention– Comparison intervention (if appropriate)– Outcomes

• Example– In an elderly patient with congestive heart

failure, are beta blockers helpful in reducing morbidity and mortality without excess side effects?



Lecture b

Four categories of foreground questions

• Intervention (or Therapy) – benefit of treatment or prevention

• Diagnosis – test diagnosing disease

• Harm – etiology or cause of disease

• Prognosis – outcome of disease course



Lecture b

Questions To Ask About The Results From Any Study

• Are the results valid?

• Are the results important?

• Can the results be applied to patient care?

• Specific sub-questions depend on type of question and study



Lecture b

Evidence-Based PracticeSummary – Lecture b

18

• There are many easily accessible resources for EBM• Approach has changed over the years• Can be best viewed from the 4S model demonstrating

the hierarchy of evidence, based on a foundation of studies, brought together where possible by syntheses, summarized in synopses, and implemented in systems that make it actionable

• When seeking evidence, it is critical to appropriately phrase the clinical question

Health IT Workforce Curriculum Version 3.0/Spring 2012


Lecture b

Evidence-Based PracticeReferences – Lecture b



Lecture b

References

Centre for Evidence Based Medicine - Homepage. (n.d.). Retrieved December 14, 2011, from Centre for Evidence Based Medicine website: http://www.cebm.net/

Centre for Evidence-Based Medicine, Toronto - Homepage. (n.d.). Retrieved December 14, 2011, from KT Clearninghouse website: http://ktclearinghouse.ca/cebm/

Centre for Health Evidence - Homepage. (n.d.). Retrieved December 14, 2011, from Centre for Health Evidence website: http://www.cche.net/

Clancy, C., & Eisenberg, J. (1998). Outcomes research: measuring the end results of health care. Science, 282, 245-246.

DiCenso, A., Bayley, L., & Haynes, R. (2009). ACP Journal Club. Editorial: Accessing preappraised evidence: fine-tuning the 5S model into a 6S model. Annals of Internal Medicine, 151(6), JC3-2, JC3-3.

Evidence Based Medicine. (2009, November 11). Retrieved December 14, 2011, from Netting the Evidence - Blog website: http://www.nettingtheevidence.org.uk/

Guyatt, G., Rennie, D., Meade, M., & Cook, D. (2008a). Users' Guides to the Medical Literature: A Manual for Evidence-Based Clinical Practice. New York, NY: McGraw-Hill.

Guyatt, G., Rennie, D., Meade, M., & Cook, D. (2008b). Users' Guides to the Medical Literature: Essentials of Evidence-Based Clinical Practice. New York, NY: McGraw-Hill.

Haynes, R. (1999). Can it work? Does it work? Is it worth it? British Medical Journal, 319, 652-653.

Haynes, R. (2001). Of studies, syntheses, synopses, and systems: the "4S" evolution of services for finding current best evidence. ACP Journal Club, 134, A11-A13.

Haynes, R. (2006). Of studies, syntheses, synopses, summaries, and systems: the "5S" evolution of information services for evidence-based healthcare decisions. Evidence-Based Medicine, 11, 162-164.

Evidence-Based PracticeReferences – Lecture b (continued)



Lecture b

Charts, Tables, Figures

5.1 Figure: Adapted from Mulrow, 1997) Mulrow, C., Cook, D., & Davidoff, F. (1997). Systematic reviews: critical links in the great chain of evidence. Annals of Internal Medicine, 126, 389-391.

5.2 Figure: Adapted from Hayne’s “4S” model of the Hierarchy of Evidence: Haynes, R. (2001). Of studies, syntheses, synopses, and systems: the "4S" evolution of services for finding current best evidence. ACP Journal Club, 134, A11-A13.

5.3 Figure: Adapted from Hayne’s “4S” model of the Hierarchy of Evidence with types and sources of evidence: Haynes, R. (2001) Of studies, syntheses, synopses, and systems: the "4S" evolution of services for finding current best evidence. ACP Journal Club, 134, A11-A13.

Reference (continued)

Hersh, W. (1999). "A world of knowledge at your fingertips": the promise, reality, and future directions of on-line information retrieval. Academic Medicine, 74, 240-243.

Mulrow, C., Cook, D., & Davidoff, F. (1997). Systematic reviews: critical links in the great chain of evidence. Annals of Internal Medicine, 126, 389-391.

PubMed Health Homepage. (n.d.). Retrieved December 14, 2011, from US National Library of Medicine website: http://www.ncbi.nlm.nih.gov/pubmedhealth/

PubMed Homepage. (n.d.). Retrieved December 14, 2011, from National Institutes of Health - US National Library of Medicine website: http://www.ncbi.nlm.nih.gov/pubmed/

Slawson, D., & Shaughnessy, A. (2005). Teaching evidence-based medicine: should we be teaching information management instead? Academic Medicine, 80, 685-689.

Straus, S., Richardson, W., Glasziou, P., & Haynes, R. (2005). Evidence Based Medicine: How to Practice and Teach EBM, Third Edition. New York, NY: Churchill Livingstone.

The Culture of Healthcare Evidence-Based Practice Lecture b This material (Comp2_Unit5b) was developed by Oregon Health and Science University, funded.

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