Primer on evidence-based medicine

Question 1

Examination of the evidence from clinical research to justify the diagnosis, prognosis, and treatment of patient

Answer 1

definition of evidence-based medicine (EBM)

Question 2

What is the new school of thought on EBM?

Answer 2

Observations can be biased

- need a systematic scientific approach to analyze the observations

Question 3

Meta-analysis
Systematic review
Randomized controlled trial
Cohort studies
Case-control studies
Case series/ case reports
Animal research/ laboratory studies/ cadaveric studies

Answer 3

Levels of evidence (best is on top)

Question 4

1) Ask - frame the research question (PICOT)
2) Acquire the evidence
3) Appraise and apply the evidence

Answer 4

Steps to analyze literature

Question 5

PICOT

Answer 5

a way to craft your question in a way that is focused and clinically answerable

Question 6

P in PICOT

Answer 6

P - patient

- who or what are you studying?

Question 7

I in PICOT

Answer 7

I - intervention

- what is the treatment or therapy?

Question 8

C in PICOT

Answer 8

C - comparison

- what are you measuring?

Question 9

O in PICOT

Answer 9

O - outcomes

- what do you want to measure or prove?

Question 10

T in PICOT

Answer 10

T - type of study

- do you want to study about therapy, diagnosis, prognosis, etc?

Question 11

Best kind of research to use

Answer 11

• Always try to find a meta-analysis, systematic review, or randomized controlled trial
• studies that have a treatment and untreated (control) group

Question 12

Things to consider when looking for literature

Answer 12

Is the study randomized?
Was the follow-up complete?
Were both groups treated equally?
How many people were involved in the study (>100 is optimal, less can be okay)?
How many patient loss was there?

Question 13

Intention to treat

Answer 13

How many patients do I need to treat before I see a benefit?

ex. need to treat 11 patients before one gets better

Question 14

these studies are more common in surgical specilties

Answer 14

prognostic or case-control study

Question 15

refers to the possible outcomes of a disease and the frequency with which they can be expected to occur

Answer 15

prognosis

Question 16

• can predict any outcome, whether good or bad

- do not necessarily cause the outcomes, just be associated with them long enough to predict their development

Answer 16

prognostic factors

Question 17

patient characteristics associated with development of a disease or condition (ie older women are at increased risk for breast cancer)

Answer 17

risk factors

Question 18

patient characteristics that help predict whether the patient already with a disease or condition will recover or relapse

Answer 18

prognostic factors (note that it is different than risk factors)

Question 19

risk for bias, limits its strength as an investigative tool and that is why it’s a level 3 study

Answer 19

retrospective data (memory or charts)

Question 20

2 or more supporting RCT’s in humans, meta-analysis of RCT’s, or Cochrane Systematic Review of RCT’s

Answer 20

level A (1) - best

Question 21

1 or more supporting controlled trials in humans or 2 or more trials in an animal model

Answer 21

level B (2)

Question 22

1 supporting controlled trial, at least 2 supporting case series that were descriptive studies in humans, or expert opinion

Answer 22

level C (3)

Question 23

1) Was there a representative patient sample at a well-defined point in the course of disease?
2) Was the follow-up sufficiently long and complete?
3) Were objective outcome criteria applied in a “blind” fashion?

Answer 23

is the prognostic (case-control) study valid

Question 24

summary of medical literature

Answer 24

meta-analysis or systematic review

- both are overviews

Question 25

1) Did the review address a clearly focused question?
2) Were the criteria used to select articles for inclusion appropriate and reproducible?
3) Were the studies of high quality?
4) Was the search detailed and exhaustive? Were contacts made with authors when questions arose?

Answer 25

questions to ask for meta-analysis or systematic review