Medical statistics courses presented by the Medical and Pharmaceutical
Statistics Research Unit, University of Reading:
8-9 March Sample Size Determination in Clinical Trials
Presenters: Anne Whitehead and Patrick Kelly
10-12 March Statistical Methods for Ordered Categorical Data
Presenters: Kim Bolland and John Whitehead
full details are given below or see http://www.reading.ac.uk/mps
Sample Size Determination in Clinical Trials
Presenters: Anne Whitehead and Patrick Kelly
8-9 March 2004
Standard fee: £600 (discounts available for early booking and
academic or public sector participants - see http://www.reading.ac.uk/mps)
At the planning stage of a clinical trial a key question is "How many patients
do we need?" For a superiority trial the main objective is to provide evidence
of superior efficacy for the new therapy relative to the control. This
requires a sample size that ensures sufficient statistical power to detect a
clinically relevant improvement. Equivalence or non-inferiority trials require
sample sizes that establish with sufficient confidence that the new therapy is
respectively equivalent to or no worse than the control.
This course provides a framework for sample size determination in superiority,
non-inferiority and equivalence trials. It considers a general parametric
approach applicable to binary, ordinal, time to event or normally distributed
patient responses. Comparisons are made with other commonly used approximate
and exact methods. Extension to more than two treatments, including a
factorial design, is considered. Practical aspects such as allowance for
drop-outs, protocol violations and mid-trial sample size reviews are
addressed. The course includes practical sessions involving the use of hand
calculators and training in software packages such as nQuery Advisor and
PASS. Use of other packages is discussed.
Programme
* A general parametric approach to sample size calculations
* Binary, ordinal, time to event and normally distributed data
* A unified approach to superiority, equivalence and
non-inferiority trials
* Parallel group and cross-over designs
* Designs with more than two treatments
* Practical and ethical considerations
* Software
Statistical Methods for Ordered Categorical Data
Presenters: Kim Bolland and John Whitehead
10-12 March 2004
Standard fee: £900 (discounts available for early booking and
academic or public sector participants - see http://www.reading.ac.uk/mps)
Ordered categorical data arise from many clinical trials and epidemiological
studies. Commonly used scales include the Glasgow Outcome Scale in head
injury, where the five response categories are Good Recovery, Moderate
Disability, Severe Disability, Vegetative State and Death; the Barthel Index
and modified Rankin score in stroke; the Expanded Disability Status scale in
multiple sclerosis as well as various measures of quality of life. This
course examines the design and analysis of studies in which the primary
response is of this form.
Binary data are a special case of ordered categorical data and the course
first reviews the statistical methodology for binary data, with an emphasis
on logistic regression analysis. The generalisation from binary to ordinal
data is based on the assumption of proportional odds, and for a simple
comparison of two homogenous groups the method leads to the Mann-Whitney
test. Linear modelling and model checking are given prominence. Calculation
and review of sample sizes are examined, together with other design issues.
Methods for the analysis of repeated ordinal data based on the marginal model
and on the subject-specific model are presented and compared.
The course is extensively illustrated using examples drawn from the
presenters' consultancy experience. Many practical sessions are included,
most of which involve using SAS.
Programme
* Review of binary data analysis
* The proportional odds model
* Fitting linear models using PROC LOGISTIC
* Model checking
* Alternative models
* Ordinal data and clinical trials
* Sample size and power
* Repeated ordinal data
For further information and to book a place on either course, please visit
http://www.reading.ac.uk/mps
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