Evidence-based medicine
“Converting the knowledge gap into an answerable question”
Learning Objectives
To understand the meaning of evidence-based medicine.
To be able to ask a “focussed/answerable”
question.
To be aware that there are many different sources of health information and how to access and assess them
Evidence based medicine
Introduction
What is EBM?
Why EBM?
Steps of EBM.
Conclusion.
What is Evidence-based medicine:
"Evidence based clinical practice is an approach to decision making in which the clinician uses the best evidence available, in consultation with the patient, to decide upon the
option which suits that patient best".
Muir Gray JA. (1997) Evidence-based healthcare: how to make health policy and management decisions.
London: Churchill Livingstone.
What is Evidence-based medicine?
EBM is an approach to practice and teaching that integrates
pathophysiological rationale,
caregiver experience, and patient preferences with valid and current clinical research evidence.
(Ellrodt, G. Evidence-based disease management, JAMA 1997, 278, 20)
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What is Evidence Based Medicine (EBM )
Is the integration of best
research evidence with clinical expertise and
patient values.
Evidence-based medicine
A process of turning clinical problems into questions...
...and then systematically locating,
appraising and using contemporaneous research findings as the basis for
clinical decisions.
Rosenberg W and Donald A. Evidence-based medicine: an approach to clinical problem- solving. British Medical Journal; 310: 1122-1127.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2549505/
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Why EBM ?
Need for valid information about diagnosis, prognosis….etc.
The inadequacy of traditional sources for information because they are:
out of date (textbook)
frequently wrong (expert),
or too overwhelming in volume & too variable in validity (journals ).
Evidence:
the whats and whys
Not all “evidence” is of equal value;
Hierarchies of research design are
considered to have different strengths;
Therefore they have different values in the final conclusions we can draw from the
literature;
http://phpartners.org/tutorial/04-ebph/2-keyConcepts/4.2.7.html
Hierarchy of evidence 1
The Five Steps of EBHC
1. To convert the knowledge gap into an answerable question
2. To search for and locate the best evidence
3. To critically appraise the evidence 4. To apply evidence
5. Evaluate your performance
audit and reflect
1. How to convert the knowledge gap into an answerable question?
How to ask clinical question that you can answer?
Learn how to recognize, classify, and prioritize important patient or policy problems.
Construct clinical questions that facilitate an efficient search for evidence.
Gather important and convincing evidence from high-quality repositories of the health literature.
Systematically check best available evidence for indications of validity, importance, and
usefulness.
Interpret the applicability of evidence to specific problems, given patient preferences and values.
PI(E)COT
Participant/Population
Intervention or Exposure
Control/Comparison
Outcomes
Time
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Patient/
Population Intervention/ Outcome
Exposure Comparison
In post-
menopausal women
Treatment with HRT
Placebo/no treatment
Increase the Risk of breast cancer
Components of Clinical Questions
2. How to search for and locate the best evidence?
Colleagues
Summaries of the primary evidence
Clinical Evidence | eMedicine | FPIN Clinical Inquiries | UpToDate
Databases
MEDLINE | Cochrane Library
Electronic textbooks and libraries
ACP Medicine | Harrisons | MD Consult | Stat!Ref
Meta-Search Engines
SUMSearch | TRIP Plus: Turning Research into Practice
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Other EBM Resources :
Michigan State University, An Introduction to Information Mastery: http://www.poems.msu.edu/infomastery/
University of Virginia Health Sciences Library, Navigating the Maze:
Obtaining Evidence-Based Medical Information:
http://www.healthsystem.virginia.edu/internet/library/col lections/ebm/index.cfm
NHS Research and Development Centre for Evidence- Based Medicine http://www.cebm.net/
Netting the Evidence - A ScHARR Introduction to Evidence Based Practice on the Internet:
http://www.nettingtheevidence.org.uk/
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3. How to Critically
appraise the evidence:
It has 3 steps :
1. Is it valid?
2. Is it important?
3. Is it applicable?
4. Applying the evidence
Can you apply this valid,
important evidence in caring
for your patient?
5. How to evaluate your performance
Evaluate your effectiveness &
efficiency in steps 1-4 and seek
ways to improve them.
Barriers to EBM approach
Culture change – hard to initiate;
“Leap in the dark”;
May require increased resources,
therefore may be easier not to ask the difficult questions;
“Lies, Damned Lies and Statistics”
mindset;
Practical difficulties of getting the
evidence to where it is needed most: the medical decision-making front line.
Next up...
...the challenge of asking answerable questions!
Clinical questions 1
ABNORMALITY: is the patient well or unwell?
DIAGNOSIS: how reliable are the tests used to diagnose disease?
FREQUENCY: how often does a disease occur?
RISK: what factors are associated with an increased risk of disease?
Clinical questions 2
PROGNOSIS: what are the
consequences of having a disease?
TREATMENT: how does treatment change the course of a disease?
PREVENTION: does an intervention on well people keep the disease from
developing? Do early detection and
early treatment improve the course and outcome of the disease?
Clinical questions 3
CAUSE: What conditions lead to disease? What are the pathogenic
mechanisms of the disease? What are the triggers for the disease?
COST: how much will care for an illness cost?
Asking Answerable Questions
Why?
Focus
Provides search terms
Inclusion/Exclusion criteria
Type of evidence/information
A poorly formulated question
Does insulin do any good in diabetes?
Refining the question
Too many hits on literature search
Nothing in the literature
“This is the trouble with internet research, in my experience. The proportion of what’s useful to what’s dross dwindles very quickly and suddenly it’s like searching for something dropped down the back of a sofa and coming up with handfuls of old coins, buttons, fluff and sucked sweets. What’s important is to ask the right question.”
Robert Harris –The Ghost
Broad Narrow
Too many concepts
Difficulty to determine search strategy
Non-comparable studies
Search taking too much time
Hard to draw conclusions
Are the results generalisable
Biased conclusions
Inclusion/exclusion criteria
PI(E)COT
Participant/Population
Intervention or Exposure
Control/Comparison
Outcomes
Time
A focused Question
P –Diabetic Patients with Type I diabetes who experience severe hypoglycaemia
I –Continuous subcutaneous insulin infusion
C –Multiple daily insulin injections
O –Reduction in hypoglycaemic rate
The role of Health
Intelligence in Evidence – Based Health Care
“Converting the knowledge
gap into an answerable
question”
Evidence-based medicine
Evidence-based medicine
Together, the two twinned units
satisfy the vision of the HI Department;
taken from HSE website:
“The work of the team brings a
heightened specialisation in regard to
the analysis of health information, a refreshed approach to using the
evidence base of health, and
support and leadership in research and development”
What is Health Intelligence?
It is responsible for capturing, utilising and developing knowledge to improve health outcomes for the population.
Use of data sources to drive health policy.
Health intelligence provides
Health information including
HIPE analysis and commentary
Demographic data
Mapping services
Evidence based Health Care
Support
Teaching
Advice on research projects and applications
Health Technology Assessment (HTA) and Health Impact Assessment (HIA)
Knowledge Management
Some Tools and Data
Sources for EBM
Health Atlas
Open source application
developed to bring health related
datasets, statistical tools and GIS
together in a web environment to add value to existing
health data;
Enables “joined up thinking” with and between agencies.
Health Atlas
Health Atlas
Health Atlas
Health Atlas
Health Atlas
Health Atlas
Health Atlas
Health Atlas
Health Atlas
Health Atlas
Health Atlas
Some questions answered by EBM within Health
Intelligence:
Primary care resource allocation.
Emergency Services provision.
Road traffic accidents.
Lower Extremity Amputations in Diabetic Patients
Rise in COPD mortality and in-patient admissions in women
Trends in paediatric hospital admissions and prescribing for asthma in Ireland over a ten year study period.
The epidemiology of assault-related hospital in-patient admissions and emergency department attendances.
