PHARM 3823 Health & Biostats Evidence-Based Medicine or Please Pass the PICO… Frederic Murray...
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Transcript of PHARM 3823 Health & Biostats Evidence-Based Medicine or Please Pass the PICO… Frederic Murray...
PHARM 3823Health & BiostatsEvidence-Based Medicineor Please Pass the PICO…
Frederic Murray Frederic Murray Assistant ProfessorAssistant ProfessorMLIS, University of British ColumbiaMLIS, University of British ColumbiaBA, Political Science, University of IowaBA, Political Science, University of Iowa
Instructional Services LibrarianInstructional Services LibrarianAl Harris Library Al Harris Library [email protected]
Peer Reviewed
Evidence Based Medicine
• Evidence-based medicine (EBM) is using and carrying out practices based on the best available knowledge.
Clinical ExpertiseEBM Best Research
Patient Preferences
Why Evidence Based Medicine?
• Exponential Growth in Medical Literature
• Impossible for Medical Practitioners to keep up
• http://tinyurl.com/d9dvuz5
Why Evidence Based Medicine?
• There are 7827 articles relevant to family practice published every month
• That’s 17 articles a day (every day) to keep up…20 hours a day reading.
Why Evidence Based Medicine?
• There are a lot of Evidence Based Review Sources that Synthesize and critically appraise healthcare literature
• They can be found in Your Library
• Also….you’ll be needing this again in Pharm 4302 Drug Information
Yale University School of Medicine
Filtered Information Appraises the quality of studies and often make recommendations for practice
Unfiltered Evidence is not always available via filtered resources. Searching the primary literature may be required
Evidence-Based MedicineFive fundamental steps
• Step 1: Formulating a well-built question
• Step 2: Identifying articles and other evidence-based resources that answer the question
• Step 3: Critically appraising the evidence to assess its validity
• Step 4: Applying the evidence
• Step 5: Re-evaluating the application of evidence and areas for improvement
The fundamental skill necessary to conduct evidence-based medicine is learning to design a Well-Built Clinical Question.
Step 1: Well Built Question• With clinical cases, there is often
a barrage of details to digest.
• To effectively search EBM resources, you need to decide what details are important.
Step 1: Well Built Question • what about the Population?• what about the Intervention?• what about the Comparison?• what about the Outcome?
P The patient’s disorder or diseaseI The intervention or finding under reviewC A comparison intervention (if applicable)O The outcome
PICO
Pico: Example
• “In a 55-year-old man with a 35-year-old history of chronic smoking, would the administration of bupropion as compared to a nicotine replacement therapy (NRT) be a better therapy in causing long-term abstinence from smoking?
PICO Example • “In a 55-year-old man with
a 35-year-old history of chronic smoking, would the administration of bupropion as compared to a nicotine replacement therapy (NRT) be a better therapy in causing long-term abstinence from smoking?
PICO Example
PICO: A State of Mind
• A systematic way to identify important concepts in a case
• Formulate a question for searching
• Often you will often not have a comparison intervention
Framing Good Questions
• Describe the subject– How would I describe a group of patients
similar to this one?”
• Define which intervention– x-ray versus an MRI
• Define the type of outcome– changes in a physical sign– outcome of a diagnostic test– response to therapy
I Class Exercise: Worksheet 1a#
• A nine-year-old girl presents in the ER with diffuse abdominal pain and loss of appetite. You suspect appendicitis, and need to decide which imaging modality is best for making the diagnosis—CT or ultrasound.
I Class Exercise: Worksheet 1a#
P Child with suspected appendicitisI CTC UltrasoundO Reliable diagnosis of appendicitis
Is ultrasound or CT better for diagnosing appendicitis in a child?
Step 2: Database/Resource Searching
• General information (background) resources
• Filtered resources• Unfiltered resources.
These resources generally fall into three categories
Build a Broader Lexicon: (MeSH)Worksheet 1b#
• Use MeSH to discover new terms
• Search MeSH to find new entry terms
for ultrasound… (in class we’re only concerned with the
C in PICO…[for now])
MeSH is the National Library of Medicine's controlled vocabulary thesaurus
General Resources
• Stedman's Online Medical Dictionary– Database
• Current Diagnosis and Treatment– Ebrary
• Drug information handbook –Lexi-Comp– 2nd floor Library
Filtered Resources
• Used to decide on a course of action for a patient (diagnosis, treatment, etc.)
• Clinical experts pose a question and then synthesize "evidence" to state conclusions based on the available research.
• The literature has been searched and results evaluated to provide an answer to a clinical question
Filtered Resources
• Annual Reviews Online
• Cochrane Database of Systematic Reviews (CDSR)
• National Guideline Clearinghouse
National Guideline Clearinghouse
• Hypertension– Age of Target Population– Guideline Category– Intended Users
Unfiltered Resources
• Search the unfiltered resources to see if any new research has been done
• Unfiltered resources provide the most recent information…but
• Not designed for answering clinical questions
• Evaluation takes time, effort and expertise
Unfiltered Resources
• Medline
• Medline PubMed
• CINAHL
• OVID
Search Example
II. Class Exercise:Search Otitis Media
• Cochrane Database of Systematic Reviews (CDSR) Filtered
• MedLine Plus Unfiltered
• Stedman's Online Medical Dictionary General
Step 3: Critical Appraisal
• If the study is from a primary source (one that provides original data on a topic with no commentary)
• Do a “validity” (closeness-to-truth) check
Dachs, R., Darby-Stewart, A., & Graber, M. (2012). Antibiotics for acute otitis media in young children: the case of the shifting end points. American Family Physician, 85(2), 104.
Step 3: Critical Appraisal
• Diagnosis • Therapy• Harm• Prognosis
Step 3: Critical Appraisal
Diagnosis• Did patient sample
include appropriate spectrum of patients to those found in general practice?
• Was the gold standard applied to all cases?
• Was the assignment of patients to treatment groups randomized?
• Were all enrolled patients accounted for at the conclusion of the study?
• Were the treatment groups similar at the start of the study?
Therapy
Step 3: Critical Appraisal
Harm • Were exposures and
outcomes measured similarly?
• Was the follow-up adequate?
Prognosis • Was the patient
sample representative?
• Was the length of the follow-up adequate?
• Was the follow-up complete?
III. Class Exercise: Therapy Questions
Dachs, R., Darby-Stewart, A., & Graber, M. (2012). Antibiotics for acute otitis media in young children: the case of the shifting end points. American Family Physician, 85(2), 104.
•Was the assignment of patients to treatment groups randomized?•Were all enrolled patients accounted for at the conclusion of the study?
•Were the treatment groups similar at the start
of the study?
Step 4: Applying the Evidence• Decide how the study and/or other
information applies to your question
– Diagnosis – Therapy– Harm– Prognosis
Step 4: Applying the Evidence
Diagnosis• Is the test available,
accurate and affordable?
• Can I estimate the pretest probability of the disease in question?
Therapy• According to the study
results how much would my patient benefit from the treatment?
Step 4: Applying the Evidence
Harm • Can the study results
be applied to my patient?
• Are there alternative therapies?
• What is my patient’s risk for adverse effects?
Prognosis
• How will the evidence influence my choice of treatment?
Step 5: Re-evaluating the Evidence
• Was the diagnosis and treatment successful?
• Is there new information/data in the literature?
• How can I improve and/or update my clinical decisions?
HOW TO MANAGE ALL THIS INFORMATION?
IV. Class Exercise
Worksheet 1c#– Research the PICO Question:Is ultrasound or CT better for
diagnosing appendicitis in a child? – Select two filtered & one unfiltered
database– Record your findings ( hint: use the
abstracts)
V. Class Exercise
Worksheet 2#– Develop PICO Questions for the case
studies – Search Filtered/Unfiltered database
to answer your question (1 source) – List Citation (APA)
Thanks!