LEEDS MEDICAL STATISTICS GROUP SEMINAR
The next seminar in our series will be:
Prof. DEBORAH ASHBY
from St Bart's & the Royal London MDS.
"Casting a sceptical eye over the data: implementing Bayesian
data monitoring in cancer clinical trials"
2pm, Friday 5th February, 1999.
Abstract:
Many clinical trials organisations use regular interim analyses
to monitor the accruing results in large clinical trials. Classical
rules, such as the group-sequential procedures of Peto, O'Brien
and Fleming or Pocock have traditionally been based on P-values.
However, none of these rules formally assess the impact that the
results of a clinical trial might have on clinical practice. Thus
a trial might be terminated early because of apparent treatment
benefit, but fail to influence future clinicians to modify their
future treatment policy. Bayesian rules have been proposed that
have the potential to overcome these difficulties (Freedman,
Spiegelhalter and Parmar, Statistics in Medicine, 1994). Like
many Bayesian techniques, they were originally presented as
reanalyses of trials that have already been published. They
are now being used `live' (Fayers, Ashby and Parmar, Statistics
in Medicine, 1997). We present details of their implementation
in a trial of surgery with and without pre-operative chemotherapy
for oesophageal cancer.
Practical issues encountered will be discussed, including
the choice of prior distribution and `clinically relevant'
values for use in monitoring, and presentation of ideas to
clinical members of the data monitoring committee. As one
clinician put it `It's just casting a sceptical eye over the data'.
Seminars are held at 34 Hyde Terrace, Leeds University.
Everybody welcome.
Further details and directions are available from Darren Greenwood.
Email: [log in to unmask]
Phone: 0113 233 4831
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