This problem is mainly for ML engineers who may not have talked to domain expert or clinicians / end users.
Pitfall 1 : sampling bias
"whos included in the analysis"
"who in your EHR"?
- e.g., - COVID prediction dataset where missing all blood tests were removed, but this missingess has a meaning. Thus not generalisable.
e.g., yesterday I mentioned about females < 6% of sample popn
Other pitfall: Inability to "time-travel"
e.g., using length of stay outcomes for example.
Pitfall 4: Hazards of measurement frequency
- icu data collected continuously. this is not random!!
- sicker patients got CVP and more frequent ABG
-measurement frequency is informative!
This means if you build a model based on frequency of lactate modelling, are you telling the clinicians anything 'new' - they know its sick hence doing frequent ABG.
Pitfall 5: overinterpretation of findings
-causal inference from observational data is DOABLE
- but WITH CARE!
e.g., if predicted risk according to predictive model increases with blood pressure, it does NOT necessarily imply that reducing blood pressure reduces risk.
@_hylandSL@ESICM Pitfall 6: implementation challenges
-just because you used EHR to build a model doesnt mean it can be implemented on EHR.
- where does the model live?
- how are you going to host?
- what data model ingest and how?
- need informatics team and infrastructure restricted ennviron.
@_hylandSL@ESICM Summary: 1. sample selection bias 2. imprecision in variable definitions 3. reliance on data not yet collected 4. informative measurement and missingness 5. overinterpreation of findings 6. implementation and EHR integration.
and many more :P
@_hylandSL@ESICM What can you do?
- be careful
- ask many questions
- follow STROPE/ TRIPOD guidelines
-have right team - interdisciplinary, statisticians, ML experts, epidemiologists, people familiar with EHR databae
-DONT DO EVERYTHING YOURSELF !
what an insightful talk @_hylandSL@ESICM#ai
Mariangela PELLEGRINI
Uppsala- Sweden
"Do we Need a biological definition of ARDS"
- Berlin definition has NO Diffuse alveolar damage .
- the Berlin defn does not capture well
Frohlich - different definitions specificity of 0.63, 0.42, 0.31 even! #ventilation#ards#LIVES2022
ARDS - new definition or phenotypes by @GicoBellani refreshing with Kigali definition of ARDS - useful not just low resource but during pandemic in supposedly high income settings and only draw back is no PEEp requirement #ards#ventilation#LIVES2022@ESICM
@GicoBellani@ESICM Resolved versus confirmed ARDS
- prospectively applying Berlin definition did work but if ya wait 24 hrs and re-measure P/F ratio, you end up stratifying much better.
- Better separation of groups
NEXT Speaker : VA ecmo for which patients?
Alain COMBES
Severe cardiogenic shock has different phenotypes 1. medical cardiogenic shock(AMI, end stage dilated CM, myocarditis, septic shock) 2. Post cardiotomy refractory CS (post CABG) #LIVES2022 @ESICM#ecmo#resuscitation#ALS
@ESICM 2022 what do the guidelines say
- ESC recommends short term MCS should be considred in cardiogenic shock.
IABP may be considered but not routinely recommended in post MI #LIVES2022