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Tuesday, June 30 (2015); Cardiology
Monday, June 29 (2015); Research methods and statistics, Statistics and Interpretation of Evidence
Clinically meaningful outcomes: something meaningful to the patient; eg.
- quality of life
Surrogate outcomes: something meaningful to the intensivist; eg.
- blood pressure, urine output
So, surely surrogate outcomes are worth pursuing? There must be some benefit to maintaining normoxia, and that must have some sort of positive influence on survival... right?
LITFL has the dummie's guide to clinical trial design.
The keywords to memorise but not necessarilty understand are as follows:
This topic is covered by the LITFL entry, Hazard Ratio, Median Ratio and Kaplan-Meier Curves. It refers to curves of events over time, eg. survival over time.
Trials have a planned end goal. They are planned to end when
As data piles up, interim analysis is carried out.
This short of analysis should be performed according to certain validity-preserving criteria:
"A confounder is a factor that is prognostically linked to the outcome of interest and is unevenly distributed between the study groups"
Confounding leads to an error in the interpretation of a measurement.
Your measurement might be accurate, but if "confounded" you may attribute it to the wrong cause.