jeremy howick centre for evidence-based medicine
TRANSCRIPT
Jeremy Howick
Centre for Evidence-Based Medicine
1. There are no hierarchies
2. EBM has always
recognized mechanisms
3. Philosophers of science have ignored
problems with the evidential role of
mechanisms
4. The fact that ‘mechanistically
sound’ hypotheses are more believable
is irrelevant.
5. The best way to improve evidence
would be to have a minimum effect size
requirement
1. There are no hierarchies: GRADE
Downgrade for:- Inconsistency- Indirectness- Imprecision- Publication bias
Upgrade for:- Large consistent effect- Dose response- Confounders only reducing size of effect
HIGHMODERATELOWVERY LOW
Step 1: Initial ranking
Step 2: upgrade/downgrade
Step 3: assign final grade
RT:HighOS:low
1. There are no hierarchies: OCEBMPICK A BOX!
randomized trial
Cohort StudyCase Series
Mechanistic reasoning
systematic review
2. EBM has always recognized a role for mechanisms
3. Proponents of mechanisms have ignore problems with mechanisms
4. Getting the contrast class right
4. Effect size
1. There are no hierarchies
2. EBM has always
recognized mechanisms
3. Philosophers of science have ignored
problems with the evidential role of
mechanisms
4. The fact that ‘mechanistically
sound’ hypotheses are more believable
is irrelevant.
5. The best way to improve evidence
would be to have a minimum effect size
requirement
Thanks again!