Evidence Based Medicine

Question 1

EBM

Answer 1

integration of clinical expertise, patient values, and the best research evidence into the decision making process for patient care

Question 2

clinical expertise

Answer 2

clinician’s cumulated experience, education, and clinical skills

Question 3

steps in practicing EBM

Answer 3

1. define the clinical question
2. find the evidence
3. analyze the evidence
4. summarize & apply the evidence and assess the outcome

Question 4

EBM practice requirements

Answer 4

Assess
Ask
Acquire
Appraise
Apply

Question 5

assess the patient

Answer 5

a clinical problem or question arises in the care of the patient

Question 6

ask the clinical question

Answer 6

utilize PICO

Question 7

PICO

Answer 7

P - patient or population (age/sex/race)
I - intervention (tests, therapy, etc)
C - comparison group (compare to nothing, to a placebo, or another intervention method)
O - outcome of interest (what do you hope to accomplish? what is the clinical effect?)

Question 8

acquire the evidence

Answer 8

select the appropriate resources and conduct a search

Question 9

appraise the evidence

Answer 9

for validity and applicability

Question 10

apply the results

Answer 10

integrate evidence with clinical expertise and patient preferences and apply it to the practice of medicine

Question 11

benefits of a well formulated question

Answer 11

save time by finding evidence that is relevant to patients’ clinical needs and directly address our knowledge needs

allows high-yield search strategies

clearer communication when sending or receiving a patient in referral

Question 12

evidence pyramid

Answer 12

1 - background information
2 - case controlled studies
3 - cohort studies
4 - randomized controlled trials
5 - critically-appraised individual article
6 - critically-appraised topics
7 - systematic reviews

Question 13

case controlled studies

Answer 13

are retrospective observational studies of a particular diagnosis or exposure

can establish correlations but cannot prove causation

Question 14

cohort studies

Answer 14

compare two groups of subjects over time, one having a particular condition or receiving a particular treatment, the other not

used when a randomized controlled trial would be unreasonable or unethical

Question 15

randomized controlled studies

Answer 15

randomly assigns subjects into treatment group or a control group to compare efficacy of a treatment, diagnosis, or drug

Question 16

critically appraised topics

Answer 16

synthesize results from several studies on a particular topic and provide the best available evidence to a specific clinical question

Question 17

systematic reviews and meta-analysis

Answer 17

comprehensively synthesize and critically appraise information from various articles that meet specific selection criteria

provide recommendation based on the best evidence available

Question 18

bayes’ theorem

Answer 18

calculates the probability of a future event given already occurred events (IE: the prob that a bucket of balls is all red (A) given the first three balls drawn were red (B))

p(A|B) = p(A + B)/p(B)

Question 19

statistical power

Answer 19

ability of a study to detect a (statistically significant) difference, if it really exists

poorly designed study = low power study

Question 20

regression to the mean

Answer 20

In an experiment, if the first value is extreme, the next measurement will be closer to the mean (or vice versa). This seems to show a significant change (wrt studies on treatment potential), but is actually completely random

Question 21

research questions should be

Answer 21

specific, answerable, novel, and relevant

Question 22

research q types

Answer 22

descriptive
evaluative
explanatory

Question 23

interventional studies

Answer 23

• test the effect of treatment or method of care
• controls not always used, but allow for comparative efficacy
• randomization is the best way to ensure comparisons are concurrent and unbiased

Question 24

why randomize?

Answer 24

• removes bias of subject characteristics
• provides for fair conclusions
• allows blinding
• prevents sicker patients from being given particular treatment

Question 25

crossover

Answer 25

patients serve as their own control

Question 26

bradford-hill criteria for causation

Answer 26

1. strength of association
2. consistency in different studies
3. specificity of association with particular disease
4. temporal relationship (temporality) (exposure predates disease)
5. biological gradient (dose-response relationship)
6. plausibility
7. coherence (consistent with what is known)
8. experiment (reversibility)
9. existence of analogous evidence (consideration of alternate explanations)