lecture 1: evidence based decision making

Question 1

What is evidence-based medicine?

Answer 1

integration of best research evidence with our clinical expertise and our patients unique values and circumstances

Question 2

What is the 5-step process of evidence-based healthcare?

Answer 2

Formulate the clinical question
Search for the best evidence available
Critically appraise the evidence (validity, relevance and applicability)
Apply the evidence in practice
Auditing evidence based decisions

Question 3

How can you formulate a clinical question?

Answer 3

Patient
Intervention
Comparison (if appropriate)
Outcome
PICO

Question 4

how can you use OR or AND to search for evidence?

Answer 4

OR: more results
AND: less results

Question 5

What level of evidence can you get?

Answer 5

Systemic reviews
randomised clinical trials (RCT)
controlled clinical trials
uncontrolled data (case reports)

Question 6

How can you critically appraise the evidence?

Answer 6

Validity (risk of bias)
-Randomisation- need to ensure randomization was performed correctly
-Concealment- was random allocation concealed from those conducting trial
-all patients accounted for- how many of those recruited completed the trial?

Clinical importance
magnitude of treatment effect
how precise is the estimate of treatment effect

Question 7

What is the definition of relative risk?

Answer 7

the ratio of the probability (‘risk’) of an event in the intervention group compared to that in the control group

A relative risk of 1 means there is no difference in risk between the two groups.

Question 8

What is absolute risk reduction?
What is number needed to treat?

Answer 8

Absolute risk reduction (the difference in risk of an event in the treated group and the control group)

Number needed to treat (the number of patients who need to be treated to achieve one additional bad or good outcome)

NNT is the inverse of the Absolute Risk Reduction (ARR)
i.e. NNT=1/ARR or 100/ARR(%)

Question 9

What does number need to treat tell you about a trial?

Answer 9

popular method of reporting the effectiveness of treatments in clinical trials

Question 10

What must you consider when applying evidence to your scenario?

Answer 10

Is your patient similar to the patients in the trial (age, co-morbidity, compliance, side effects)
How much of the study effect can you expect?
Is the intervention realistic?
What are the alternatives?
Is the treatment acceptable to your patient?