EBM Exam 2

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  1. Clinical endpoint
    • some type of occurrence of an event or outcome
    • can be time of an event
    • reflects functioning or survival
  2. concentrating on an endpoint may
    overlook other benefits
  3. 5 Qualities of an ideal endpoint
    • relevant
    • accurate
    • precise
    • reliable
    • assessable
  4. Prior to data collection, it is important to
    define a single primary endpoint
  5. Most trials measure
    many endpoints
  6. Co-primary endpoints
    • used when benefit of just one endpoint is not sufficient
    • ex. immediate cardiac failure (w/in 2 hours) and mid-term mortality (14 days)
  7. Binary clinical endpoints
    • "in our study we defined HTN as DBP >95 mmHG."
    • simple to understand
    • more clinically relevant
  8. Continuous endpoints
    • "In our study we measured DBP in mmHG over a six month period"
    • increased efficiency (fewer pt needed)
    • Avoid arbitrary cut-off values
  9. Why are randomized control trials not always practical?
    • too costly (2 phase two trials = cost of 1 RTC (phase 3) trial)
    • time consuming
    • require too many patients
  10. Surrogate marker
    biomarker that is intended to substitute for a clinical endpoint
  11. 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
  12. Validation of surrogate endpoints
    • should be based on clinical insight and empirical evidence
    • understand pathways and MOA
    • requires meta-analysis of many trials
  13. down fall of surrogate endpoints
    easier to show effect of an intervention on clinical endpoints than to validate a surrogate marker
  14. composit endpoints
    • two or three endpoints grouped together
    • often in large CV trials
    • can blunt meaningful endpoints
  15. 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?
  16. Definition of surrogate marker
    • laboratory, radiologic or physically assessed measure believed to correlate with clinically important outcome
    • ex. BP, BG...
  17. concerns with surrogate markers
    surrogate outcome may not correlate with clinically important outcomes
  18. 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
  19. definition of composite endpoint
    endpoint consisting of two or more individual endpoints grouped together
  20. concerns with composite endpoints
    may amalgamate different endpoints of unequal clinical importance making it difficult to interpret effects of an intervention.
  21. impact of composit endpoints on a study's power
    increased since multiple endpoints are amalgamated together, increaseing event rates
Card Set:
EBM Exam 2
2012-02-29 16:28:29
Clinical Endpoints Selection Concerns

Clinical Endpoints-Selection and Concerns
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