BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Assessing surrogacy using linear mixed models and the surrogate th
 reshold effect - Dr. Sally Galbraith\, School of Mathematics and Statistic
 s\, The University of New South Wales\, Australia
DTSTART:20110607T133000Z
DTEND:20110607T143000Z
UID:TALK30833@talks.cam.ac.uk
CONTACT:Li Su
DESCRIPTION:A surrogate outcome is a biomarker that is used as a substitut
 e for the true outcome\, for the purpose of assessing treatment efficacy i
 n a Phase III clinical trial. In situations where measurement of the most 
 relevant clinical outcome may be difficult\, costly\, invasive\, or requir
 e a long follow-up time\, use of a more easily or cheaply measured surroga
 te outcome allows more rapid or less costly evaluation of treatments. On t
 he other hand\, inappropriate use of a biomarker as a surrogate can be dan
 gerous\, as illustrated by the infamous CAST experience. Hence a potential
  surrogate needs to be “validated” before use.\n\nThis talk will revie
 w some of the statistical methods proposed for evaluating potential surrog
 ates\, and describe a meta-analytic approach based on a bivariate normal l
 inear mixed model proposed by Buyse et al. (2000). The surrogate threshold
  effect has been has been suggested as a useful measure of surrogacy that 
 is conceptually meaningful to clinicians. Statistical properties of this m
 easure will be considered\, and illustrated via the results of some simula
 tion studies.\n
LOCATION:Large Seminar Room\, 1st Floor\, Institute of Public Health\, Uni
 versity Forvie Site\, Robinson Way\, Cambridge
END:VEVENT
END:VCALENDAR