WEEK 1: DECISIONS AND EVIDENCE

Question 1

What is evidence?

Answer 1

*Clearness, obviousness,
indication, sign, facts making for a conclusion, in support of,

*Information (given personally, or drawn from documents etc.) tending to establish fact,
serve to indicate, attest.

Question 2

What is evidence-based medicine?

Answer 2

Conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients.

The practice of evidence- based medicine means integrating individual clinical expertise with the best available external clinical evidence from systematic research.

Question 3

What determines the quality of the evidence?

Answer 3

The quality which is informed by:
*The methods (study design) used to investigate the problem
*The source of that information.

Question 4

State 5 factors that can lower the quality of evidence.

Answer 4

1. limitations in detailed design and execution (risk of bias criteria)
2. Inconsistency (or heterogeneity)
3. Indirectness (PICO and applicability)
4. Imprecision (number of events and confidence intervals)
5. Publication bias

Question 5

Ste 3 factors that can increase the quality of evidence.

Answer 5

1. large magnitude of effect
2. all plausible residual confounding may be working to reduce the demonstrated effect or increase the effect if no effect was observed
3. dose-response gradient-

Question 6

State the value of recognizing the quality of evidence.

Answer 6

*Failure to consider the quality of evidence can lead to misguided recommendations; hormone replacement therapy for post-menopausal women provides an instructive example

*High quality evidence that an intervention’s desirable effects are clearly greater than its undesirable effects, or are clearly not, warrants a strong recommendation

*Uncertainty about the trade-offs (because of low quality evidence or because the desirable and undesirable effects are closely balanced) warrants a weak recommendation

Question 7

What provides a system for rating quality of evidence and strength of recommendations?

Answer 7

The Grading of Recommendations Assessment, Development and Evaluation (GRADE ) approach provides a system for rating quality of evidence and strength of recommendations that is explicit, comprehensive, transparent, and pragmatic and is increasingly being adopted by organizations worldwide

Question 8

How does GRADE rate evidence?

Answer 8

Crucially, when using GRADE, we do not rate evidence by study by study, but across studies for specific clinical outcomes.

Question 9

State the 4 components which are assessed by the GRADE.

Answer 9

*Methodological flaws within the component studies

*Consistency of results across different studies

*Generalizability of research results to the wider patient base

*How effective the treatments have been shown to be

Question 10

How are scores or grading allocated?

Answer 10

Treatment comparisons are given one of four GRADE scores reflecting the quality of the evidence —

*high-, moderate-, low-, or very low-quality evidence.

Question 11

Describe the 6 levels of hierarchy or PYRAMID of evidence from top to bottom.

Answer 11

1.Systematic reviews
2.Critically appraised topics and articles
3.Randomized controlled trials
4.Cohort studies
5.Case control studies
6.Background information / expert opinion