EBM Exam 2
Card Set Information
EBM Exam 2
Clinical Endpoints Selection Concerns
Clinical Endpoints-Selection and Concerns
some type of occurrence of an event or outcome
can be time of an event
reflects functioning or survival
concentrating on an endpoint may
overlook other benefits
5 Qualities of an ideal endpoint
Prior to data collection, it is important to
define a single primary endpoint
Most trials measure
used when benefit of just one endpoint is not sufficient
ex. immediate cardiac failure (w/in 2 hours) and mid-term mortality (14 days)
Binary clinical endpoints
"in our study we defined HTN as DBP >95 mmHG."
simple to understand
more clinically relevant
"In our study we measured DBP in mmHG over a six month period"
increased efficiency (fewer pt needed)
Avoid arbitrary cut-off values
Why are randomized control trials not always practical?
too costly (2 phase two trials = cost of 1 RTC (phase 3) trial)
require too many patients
biomarker that is intended to substitute for a clinical endpoint
advantages of using surrogate markers
faster trial completion and drug approval
more frequent measurements
provides insight to MOA and pharmacology
guides dose selection
more efficient screening of drug candidates
less cost to mfg or sponsor
Validation of surrogate endpoints
should be based on clinical insight and empirical evidence
understand pathways and MOA
requires meta-analysis of many trials
down fall of surrogate endpoints
easier to show effect of an intervention on clinical endpoints than to validate a surrogate marker
two or three endpoints grouped together
often in large CV trials
can blunt meaningful endpoints
3 questions to validate composite endpoints
are the components of the endpoints of similar importance to patients?
did the more and less important end points occur with similar frequency?
are the component endpoints likely to have similar relative risk reductions?
Definition of surrogate marker
laboratory, radiologic or physically assessed measure believed to correlate with clinically important outcome
ex. BP, BG...
concerns with surrogate markers
surrogate outcome may not correlate with clinically important outcomes
surrogate endpoint impact on study's power
increased since surrogate endpoints like BP are more responsive to intervensions than hard clinical endpoints such as stroke
definition of composite endpoint
endpoint consisting of two or more individual endpoints grouped together
concerns with composite endpoints
may amalgamate different endpoints of unequal clinical importance making it difficult to interpret effects of an intervention.
impact of composit endpoints on a study's power
increased since multiple endpoints are amalgamated together, increaseing event rates