Block 2

Question 0

What is the EBP process?

Answer 0

Integration of best research evidence with clinical expertise and patient values

Question 1

What are the steps of the EBP process?

Answer 1

1. Assess the patient
2. Ask the question
3. Acquire the evidence
4. Appraise the evidence
5. Apply and integrate the evidence
6. Self-evaluation

Question 2

What are the steps in building a good clinical question?

Answer 2

P - patient problem
I - intervention
C - comparison
O - outcome

Question 3

What are the different types of clinical questions?

Answer 3

1. Therapy questions
2. Diagnostic test questions
3. Prognosis questions
4. Harm/Etiology questions

Question 4

What are the different types of studies, in order of ascending importance?

Answer 4

1. Animal studies
2. Case studies/case reports
3. Case control studies
4. Cohort studies
5. Randomized clinical trials
6. Systematic reviews
7. Meta-analyses

Others
Cross-sectional studies
Retrospective cohort/historical cohort
Qualitative Research

Question 5

Match study types with questions

Answer 5

*Diagnosis -> cross-sectional: a prospective, blind comparison to a gold standard
*Therapy -> RCT > cohort study
*Prognosis -> cohort study > case control > case series
Harm/Etiology -> cohort > case control > case series

Question 6

Name the different types of resources and give examples of each

Answer 6

• Pre-appraised - ACP Journal Club, Clinical Evidence, Essential Evidence, Dynamed, FPIN Clinical Inquiries, UpToDate
• Databases - Cochrane Library, PubMed, Center for Reviews and Dissemination (DARE)
• Electronic textbooks and libraries - Access Medicine, Scientific American Medicine, ACP Smart Medicine, Stat!Ref, ClinicalKey
• Meta-search engines - TRIP

Question 7

Steps in appraisal of validity

Answer 7

Are the results valid?
What are the results?
How can they help my patients?

Question 8

What are LRs, and when are they used?

Answer 8

Likelihood ratios tell the chances of having or not having a disease, based on a test outcome

• They’re used to assess the validity of diagnostic tests
• LR+ range points: 1, 2, 5, 10
• LR - range points: 1, 0.5, 0.2, 0.1

Question 9

What is sensitivity? What is specificity? When are they used?

Answer 9

Sensitivity = true positives/all positives. Probability that a person with the disease will test positive.

Specificity = true negatives/all negatives. Probability that a person without the disease will test negative.

Both are used in assessing the validity of diagnostic tests.

Question 10

What are the absolute risk reduction measurements? When are they used?

Answer 10

All used in assessing the validity of a therapy study

• EER = experimental event rate = % desired outcome present/total in experimental group
• CER = control event rate = % desired outcome present/total in control group
• ABI = absolute benefit increase = % EER - CER
• RR = relative risk = EER/CER. Proportional reduction in risk.
• RBI = relative benefit increase= % ABI/CER
• NNT = numbers needed to treat = 1/ABI

Question 11

Key issues for diagnostic studies

Answer 11

Diagnostic uncertainty
Blind comparison to gold standard
Each patient gets both tests

Question 12

Key issues for prognosis studies

Answer 12

Well-defined sample
Similar prognosis
Follow-up > 80%
Objective and unbiased outcome criteria

Question 13

Key issues for harm studies

Answer 13

Similarity of comparison groups
Outcomes and exposures measured same for both groups
Follow-ups of sufficient length (> 80%)

Question 14

Key issues for systematic reviews

Answer 14

Focused question
Thorough literature search
Include validated studies
Selection of studies reproducible

Question 15

How are prognostic results given?

Answer 15

Absolute terms, e.g. 5 yr survival rate
Relative terms, e.g. risk from prognostic factor
Survival curves, which are cumulative events over time