Choosing the right outcome measures for a Clin trial Flashcards
What are outcomes and what are endpoints?
Outcomes are measured variables (e.g. blood glucose before and after new drug or placebo)
Whereas endpoints are analysed parameters (e.g. change in blood glucose from baseline with drug)
What are exploratory endpoints?
Outcomes that are used to frame future research. (i.e. explore new hypothesis)
What are surrogate endpoints?
Are substitutes for clinically meaningful endpoints (usually a biomarker)
Explain patient reported outcomes (PRO)
Any report of the status of patient’s health condition that comes directly from the patient, without interpretation of the patient’s response by a clinician or anyone else.
What are composite endpoints?
A single endpoint that combines a combination of individual endpoints that are related.
E.g. Major adverse cardiac events (MACE); total death, MI, stroke etc.
What is the problem with surrogate endpoints?
Many surrogate endpoints that are not closely associated enough to correlate with direct outcomes therefore can lead to over interpretation of benefits.
What are the problems with composite endpoints?
- Inconsistently defined composite endpoints
- Not justified in methodology why the endpoints are combined
- Uneven weight of individual endpoints
What are the problems with subjective endpoints?
Observer bias
Detection bias
(e.g. over or under-reporting of outcomes or adverse events in unblinded clinical trials)
Complex scale problems
- Non-validated measurement scale
- Changes in measurement scale after trial initiation.
Missing data rule
‘5 and 20 rule’
If >20% missing data, then the study is highly biased; if <5% then there is a low risk of bias
What is COMET?
Core outcome measures in effectiveness trials - an initiative to support investigators to develop a ‘core outcome set’
