Table of Contents
Evidence-Based Medicine
Objectives
Logic + training + experience IS NOT ENOUGH.....
When to use Evidence
Study Design
Study types
Study types
Study types
Study types
Hierarchy of proof
True Experiment
Prospective vs. Retrospective
Harmful Exposure
Rare Disease
Disease Takes Years to Develop
Fishing Expeditions
Rules of evidence - diagnosis
Rules of evidence - treatment
Diagnosis
Diagnosis - the ideal test
Diagnosis - the usual dilemma
Diagnosis
Diagnosis
Above all.... do no harm.
Diagnosis - the box approach
Sensitivity
Diagnosis - Sensitivity (PID)
Specificity
Diagnosis - Specificity (NIH)
Diagnosis - the box approach
Diagnosis - fill in the numbers
Changing the cut-off
Diagnosis - changing cut-off
Changing the cut-off
Changing the cut-off
But the test was positive...
The test was either + or - .
Diagnosis - Pos. Pred. Value
Diagnosis - the box approach
Diagnosis - Neg. Pred. Value
Negative Predictive Value
How to go from Pre-to Post-test Probability
How to go from Pre-to Post-test Probability -
How to go from Pre-to Post-test Probability - STEP 1
How to go from Pre-to Post-test Probability - STEP 2
How to go from Pre-to Post-test Probability - STEP 2
How to go from Pre-to Post-test Probability - STEP 3
How to go from Pre-to Post-test Probability - FINAL
Threshold Decision-Making
Changing Prevalence & Sensitivity (example)
Diagnosis - the box approach
Diagnosis - the box approach
Diagnosis - the box approach
Diagnosis - the box approach
Pre- to Post-Test Probabilities different sensitivities
50% Prevalence
Prevalence < 50%
Changing prevalence
Changing sensit., specificity
Sensitivity (PID)
Pos. Pred. Value
Neg. Pred. Value - FN (Sens.)
Treatment
What was the treatment or exposure effect?
RCT/Cohort vs. Case Control
Odds Ratios & Relative Risks
Odds Ratio
Relative Risk
Odds Ratio Relative Risk
RRR, ARR, NNT
RRR, ARR, NNT
RRR, ARR, NNT
RRR, ARR, NNT
Significance
p Value & Power
Is there a difference?
95% Confidence Interval
95% Confidence Interval
Clinical vs. Statistical Signif.
Summary
APPENDIX
Rules of evidence - diagnosis
Rules of evidence - treatment
Rules of evidence - treatment
Rules of evidence - treatment
Patients - Name that Bias
Example - febrile seizure
Example - febrile seizure
Rules of evidence - treatment
Rules of evidence - treatment
Rules of evidence - treatment
Rules of evidence - treatment
Encainide & Flecainide
Encainide & Flecainide
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