Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Bayesian sample size for exploratory clinical trials incorporating historical data.
AU - Whitehead, John
AU - Valdés-Márquez, Elsa
AU - Johnson, Patrick
AU - Graham, Gordon
PY - 2008/6
Y1 - 2008/6
N2 - This paper presents a simple Bayesian approach to sample size determination in clinical trials. It is required that the trial should be large enough to ensure that the data collected will provide convincing evidence, either that an experimental treatment is better than a control, or that it fails to improve upon control by some clinically relevant difference. The method resembles standard frequentist formulations of the problem, and indeed in certain circumstances involving “non-informative” prior information it leads to identical answers. In particular, unlike many Bayesian approaches to sample size determination, use is made of an alternative hypothesis that an experimental treatment is better than a control treatment by some specified magnitude. The approach is introduced in the context of testing whether a single stream of binary observations are consistent with a given success rate p0. Next the case of comparing two independent streams of normally distributed responses is considered, first under the assumption that their common variance is known and then for unknown variance. Finally, the more general situation in which a large sample is to be collected and analysed according to the asymptotic properties of the score statistic is explored.
AB - This paper presents a simple Bayesian approach to sample size determination in clinical trials. It is required that the trial should be large enough to ensure that the data collected will provide convincing evidence, either that an experimental treatment is better than a control, or that it fails to improve upon control by some clinically relevant difference. The method resembles standard frequentist formulations of the problem, and indeed in certain circumstances involving “non-informative” prior information it leads to identical answers. In particular, unlike many Bayesian approaches to sample size determination, use is made of an alternative hypothesis that an experimental treatment is better than a control treatment by some specified magnitude. The approach is introduced in the context of testing whether a single stream of binary observations are consistent with a given success rate p0. Next the case of comparing two independent streams of normally distributed responses is considered, first under the assumption that their common variance is known and then for unknown variance. Finally, the more general situation in which a large sample is to be collected and analysed according to the asymptotic properties of the score statistic is explored.
KW - Bayesian methods
KW - clinical trial
KW - phase II trial
KW - proof-of-concept study
KW - sample size
KW - score statistic
U2 - 10.1002/sim.3140
DO - 10.1002/sim.3140
M3 - Journal article
VL - 27
SP - 2307
EP - 2327
JO - Statistics in Medicine
JF - Statistics in Medicine
SN - 1097-0258
IS - 13
ER -