1. The document outlines the evidence-based medicine (EBM) process which involves five stages: formulating a question, searching for evidence, appraising the evidence, applying to practice, and evaluating. 2. It provides examples of clinical questions and formulates them using the PICO framework. 3. It describes the different types of studies and levels of evidence to consider when evaluating different types of clinical questions related to therapy, diagnosis, etiology/harm, and prognosis. 4. Resources for both filtered and unfiltered information are presented to guide searching for evidence depending on the question type. 5. Criteria for app

1. Evidence-Based Medicine for
Obstetrics and Gynecology
L I F E S C I E N C E S L I B R A R Y
Summer 2013
Robin Featherstone, MLIS
http://www.slideshare.net/featherr

2. Why EBM?

3. Workshop - Objectives
By the end of the workshop, you will be able to:
1. Describe the five stages of the EBM process
2. Differentiate background from foreground questions
3. Develop a well-formed PICO question
4. Categorize questions and identify the best studies to
answer each question type
5. Select appropriate sources to search for evidence to best
answer your questions
6. Identify three fundamental questions to ask when
appraising a published study

4. EBM for Obstetrics & Gynecology
 Based on Hematology pilot
EBM program for
specialist residents
 Focused on real-life
clinical questions
 Aimed to integrate EBM
principles into journal
clubs, everyday practice

5. EBM Process
Appraising
the Evidence
Incorporating
evidence into
decision-making
Evaluating
the Process
Formulating
the clinical
question
Searching
the Evidence
Your patient for whom
you are uncertain about
therapy, diagnosis, or
prognosis
ASK
ACQUIRE
APPRAISE
APPLY
ASSESS

6. Guyatt G, Rennie D, Cook D. Users' Guides to the Medical Literature : A Manual for Evidence-Based Clinical Practice (2nd
Edition). New York, NY, USA: McGraw-Hill Professional Publishing; 2008.
[1.]
What are the reported
incidences of
paraovarian cysts?
What are risk factors for
pelvic inflammatory
disease?
Should a left atrial
mobile mass in an
elderly woman with a
previous uterine
sarcoma be removed?

7. [1.]
Sources for Background Questions
• Textbooks
• Handbooks
• Manuals
• Encyclopedias
• etc
Background
Questions

8. Patient Scenario
You are following a 35 year-old pregnant female for low
platelets thought to be due to immune thrombocytopenia as
she had thrombocytopenia prior to her pregnancy. During the
pregnancy, her platelets fluctuated quite a bit, ranging from
her pre-pregnant baseline of 120 to as low as 60. When she
presented to hospital in labour, her platelets count was 75
preventing her from getting an epidural, but ensuring a safe
delivery.
She undergoes a spontaneous vaginal delivery without
complications. She and the baby are medically ready to leave
the hospital 48 hours later. Her platelet count has risen to
110. She asked if she should be concerned for her
newborn, knowing that her antibodies, the same that are
causing her immune thrombocytopenia, are passed along to
baby. Should a blood test be done to check the baby’s
platelet count. If so, when?

9. Formulating a Clinical Question
Patient, population, or problem
Intervention, prognostic factor, or exposure
Comparison or intervention
Outcomes to measure or be achieved

10. What’s the PICO?
You are following a 35 year-old pregnant female for low
platelets thought to be due to immune thrombocytopenia as
she had thrombocytopenia prior to her pregnancy. During the
pregnancy, her platelets fluctuated quite a bit, ranging from
her pre-pregnant baseline of 120 to as low as 60. When she
presented to hospital in labour, her platelets count was 75
preventing her from getting an epidural, but ensuring a safe
delivery.
She undergoes a spontaneous vaginal delivery without
complications. She and the baby are medically ready to leave
the hospital 48 hours later. Her platelet count has risen to
110. She asked if she should be concerned for her
newborn, knowing that her antibodies, the same that are
causing her immune thrombocytopenia, are passed along to
baby. Should a blood test be done to check the baby’s
platelet count. If so, when?

11. PICO
P: Newborns born to mothers with immune
thrombocytopenia
I: Blood test to check platelet count
C: No blood test
O: Diagnosis of immune thrombocytopenia

12. Clinical Question
In newborn patients with suspected immune
thrombocytopenia, is a blood test to
determine platelet count recommended to
diagnose immune thrombocytopenia?

13. What is the “evidence”?
Systematic Reviews
Randomized control trials
Cohort studies
Case-control studies
Case reports
Editorials
Animal research
All types of articles found in PubMed

14. Question Best Evidence
Cost •Cost-effectiveness study
Diagnosis •Diagnostic validation studies
•Prospective studies / blind comparison to a
gold standard
Etiology/Harm •Cohort study
•Case control study
Prognosis •Cohort study
•Case control study
Quality of life •Qualitative studies
Therapy •Systematic review of Randomized Controlled
Trials (RCTs)
•Single RCT
1 Heneghan, Carl, and Douglas Badenoch. Evidence-Based Medicine Toolkit. 2nd ed. Malden, Mass.: BMJ Books/Blackwell Pub., 2006.
2 Glover, Jan, and Lei Wang. Find it Fast: The Clinical Question : www.med.yale.edu/library/education/guides/screencasts/finditfast/finditfast_2/

15. Levels of Evidence
for Therapy Question
Level of Evidence Type of Study
1a Systematic reviews of randomized controlled trials
(RCTs)
1b Individual RCTs with narrow confidence interval
2a Systematic reviews of cohort studies
2b Individual cohort studies and low-quality RCTs
3a Systematic reviews of case-control studies
3b Case-control studies
4 Case series and poor quality cohort and case-control
studies
5 Expert opinion
15
Levels of evidence (2001). Centre for Evidence Based Medicine. Retrieved 26 Aug 2008 from
http://www.cebm.net/index.aspx?o=1025

16. Unfiltered
Filtered
2a 2b
54
3b
4
1b1b
2a
5
2b
3b
Summaries
Information Sources
for Diagnosis Question
Synopsis
of
synthesis

17. 1. Soundness of evidence-based approach
2. Comprehensiveness and specificity
3. Ease of use
4. Availability
See also:
http://www.jgh.ca/en/hslinteractivepyramid
Criteria for Selecting an Information
Source

18. Filtered
Information Sources
some examples
} includes:
• Cochrane
Database of
Systematic
Reviews
• DARE (Database
of Abstracts of
Reviews of Effects)

19. Filtered
Information Sources
some examples

20. Filtered
Information Sources
some examples
Unfiltered

21. Information Sources
some examples
Unfiltered
Expert Opinion

22. Unfiltered
Filtered
Information Sources
some examples

23. Unfiltered
Expert Opinion
Filtered

24. What’s the PICO?
A 27-year-old presented for her initial prenatal visit at 10 weeks’ gestation.
Her family and medical histories were unremarkable and she reported
healthy behaviours. Her BMI was 22. She has been vegan for the
previous 5 years.
Her initial prenatal labs revealed mild anemia (hematocrit, 32%;
hemoglobin, 10.8 g/dL ). She was asked to bring a 3-day diet history so
that her food choices could be evaluated. Evaluation of her diet revealed
a deficiency of iron-rich foods and insufficient intake of foods high in
folate.
You discussed iron supplementation with the patient and she expressed
concern over the impact on the health of the baby.
Penney, et. al. (2008). Nutritional Counseling for Vegetarians During Pregnancy and Lactation. Journal of Midwifery &
Women’s Health. Vol 53. Issue 1. pg 37-44. Retrieved July 23, 2013 from http://dx.doi.org/10.1016/j.jmwh.2007.07.003

25. Possible PICO 1
P: 27 year old female with prenatal anaemia
I: Iron supplementation
C: No iron supplementation
O: Adverse pregnancy outcomes

26. Possible PICO 2
P: 27 year old female with prenatal anaemia
I: Diet modification to include iron enriched
vegetarian foods
C: No diet modification
O: Improvement in haemoglobin
concentration

27. Possible PICO 3
P: 27 year old female with prenatal anaemia
I: Iron supplementation
C: Diet modification to include iron enriched
vegetarian foods
O: Adverse pregnancy outcomes

28. Possible PICO 4
P: 27 year old female with prenatal anaemia
I: Iron supplementation
C: Diet modification to include iron enriched
vegetarian foods
O: Improvement in haemoglobin
concentration

29. For a patient with prenatal anemia, does iron
supplementation increase the risk of adverse
pregnancy outcomes?
What kind of a question is this?

30. Question Best Evidence
Cost •Cost-effectiveness study
Diagnosis •Diagnostic validation studies
•Prospective studies / blind comparison to a
gold standard
Etiology/Harm •Cohort study
•Case control study
Prognosis •Cohort study
•Case control study
Quality of life •Qualitative studies
Therapy •Systematic review of Randomized Controlled
Trials (RCTs)
•Single RCT
1 Heneghan, Carl, and Douglas Badenoch. Evidence-Based Medicine Toolkit. 2nd ed. Malden, Mass.: BMJ Books/Blackwell Pub., 2006.
2 Glover, Jan, and Lei Wang. Find it Fast: The Clinical Question : www.med.yale.edu/library/education/guides/screencasts/finditfast/finditfast_2/

31. Unfiltered
Expert Opinion
Filtered
Where are you going to look?

32. * Links to all of these resources:
http://www.mcgill.ca/library/library-
findinfo/subjects/health/medicine
Search strategies*
Cochrane (anemia OR anaemia) AND pregnan* AND iron
UpToDate (anemia OR anaemia) AND pregnan* AND iron > Treatment of the
adult with iron deficiency anemia > Pregnancy
PubMed Clinical
Queries
(anemia OR anaemia) pregnancy iron
TRIP Database (anemia OR anaemia) AND pregnan* AND iron
Google Scholar allintext: (anemia OR anaemia) ~pregnancy iron

33. EBM Process
Appraising
the Evidence
Incorporating
evidence into
decision-making
Evaluating
the Process
Formulating
the clinical
question
Searching
the Evidence
Your patient for whom
you are uncertain about
therapy, diagnosis, or
prognosis
ASK
ACQUIRE
APPRAISE
APPLY
ASSESS

34. Summarizing the Evidence (Systematic Reviews)*
1. Are the results valid?
A. Did the review explicitly address a sensible clinical question?
B. Was the search for relevant studies detailed and exhaustive?
 Were sources of evidence and search strategies specified in sufficient detail for
replication
 Was the likelihood and direction of publication bias considered?
C. Were the primary studies of high methodologic quality?
D. Were selection and assessments of studies reproducible?
*. http://jamaevidence.com/criticalAppraisalWorksheet/26

35. Summarizing the Evidence (Systematic
Reviews), cont.
2. What are the results?
A. Were the results similar from study to study?
B. What are the overall results of the review?
C. How precise were the results?

36. Summarizing the Evidence (Systematic
Reviews), cont.
3. How can I apply the results to patient care?
A. Were all patient-important outcomes considered?
B. Are any postulated subgroup effects credible?
C. What is the overall quality of the evidence?
D. Are the benefits worth the costs and potential risks?

37. 1. UpToDate is a _______ resource. And EMBASE is
a ________ resource.
2. The 5 stages in the EBM process are _______.
3. The best evidence to answer a diagnosis
question is _______.
4. To find systematic reviews of RCTs use _______.
5. PICO stands for ________.
6. The three questions to ask to appraise ANY
study are _______, ________, and ________.
Summary Quiz

38. Next steps
Some suggestions for your journal clubs (next one: August 21)
 Start with a patient case
 Develop a PICO question
 Search for best available evidence
 Appraise the article using standard questions for that study
design
 Slides available: http://www.slideshare.net/featherr