I would be grateful if list members could please bring the following
opportunity to the attention of any suitable students at BSc or MSc level.
An MRC-funded PhD studentship is available from the MRC Clinical Trials Unit
for study on the following project
Funding: The award covers fees and a tax-free maintenance stipend.
Eligibility: Full studentships are available only to UK applicants. Other EU
applicants may be eligible for a "fees-only" award.
Deadline for applications: 14 April 2006
Project topic: Methods to Perform an Analysis of the Sensitivity to
Informative Drop-Out
Institution: The student will be primarily based at the Department of
Statistical Science, UCL
Supervisors: Dr Andrew Copas (UCL) and Prof Abdel Babiker (MRC Clinical
Trials Unit).
Randomised controlled trials are frequently designed to compare the time
till a 'failure' event, such as death, between two or more therapies. Some
patients may drop-out of the study during follow-up. These patients may
differ from those who remain in the study, termed informative drop-out,
resulting in bias if standard techniques are used to analyse the data. We
can investigate the nature of the likely difference if suitable disease
markers are recorded during follow-up, for example by observing whether
drop-out tends to follow a deterioration or improvement in these markers.
Various authors have proposed techniques to incorporate information from the
markers to reduce bias from drop-out. Some techniques also allow an analysis
of the sensitivity of the study findings to a dependence of drop-out not
only on prior markers but also on subsequent survival. In this project we
will examine the practical implications of these approaches, which have
rarely been implemented, and look to extend them to (i) regression
techniques and (ii) multiple causes of drop-out. Our work will be
illustrated through simulation studies and practical application to data
from a trial comparing three strategies for initiating antiretroviral
therapy in HIV positive patients, in which 11% of patients dropped-out.
Please contact Dr Andrew Copas with any enquiries, information on how to
apply, and for further details of the project.
Dr Andrew Copas
Senior Lecturer in Medical Statistics
& Departmental Tutor
Centre for HIV & Sexual Health Research
& Department of Statistical Science
University College London
[log in to unmask] & [log in to unmask]
Tel: 020 7679 1863
http://www.ucl.ac.uk/Stats/ <http://www.ucl.ac.uk/Stats/>
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