Sample size calculations for clinical trials using the NIH Stroke Scale.

Sample size calculations for clinical trials using the NIH Stroke Scale.

Sample size calculations for randomized controlled trials.

Most informed consent documents for randomized controlled trials implicitly or explicitly promise the prospective participant that the trial has a reasonable chance of answering a medically important question. The medical literature, however, is replete with descriptions of trials that provided equivocal answers to the questions they addressed. Papers describing the results of such studies may ...

Sample size for clinical trials

An outcome variable is one which we hope to change, predict or estimate in a trial. Examples: • Systolic blood pressure in a hypertension trial • Caesarean section rate in an obstetric trial • Survival time in a cancer trial How many outcome variables should I have? If we have many outcome variables: • all possibilities would be covered, • we would be less likely to miss something, • the risk o...

A mixed Bayesian/Frequentist approach in sample size determination problem for clinical trials

In this paper we introduce a stochastic optimization method based ona mixed Bayesian/frequentist approach to a sample size determinationproblem in a clinical trial. The data are assumed to come from a nor-mal distribution for which both the mean and the variance are unknown.In contrast to the usual Bayesian decision theoretic methodology, whichassumes a single decision maker, our method recogni...

Bayesian sample size calculations in phase II clinical trials using informative conjugate priors.

A number of researchers have discussed phase II clinical trials from a Bayesian perspective. A recent article by Tan and Machin focuses on sample size calculations, which they determine by specifying a diffuse prior distribution and then calculating a posterior probability that the true response will exceed a prespecified target. In this article, we extend these sample size calculations to incl...