Statistical methods in medical research
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Stat Methods Med Res · Aug 2011
A behavioural Bayes approach to the determination of sample size for clinical trials considering efficacy and safety: imbalanced sample size in treatment groups.
The behavioural Bayes approach to sample size determination for clinical trials assumes that the number of subsequent patients switching to a new drug from the current drug depends on the strength of the evidence for efficacy and safety that was observed in the clinical trials. The optimal sample size is the one which maximises the expected net benefit of the trial. The approach has been developed in a series of papers by Pezeshk and the present authors (Gittins JC, Pezeshk H. ⋯ A Monte Carlo simulation is employed for the calculation. Having a larger group of patients on the new drug in general makes it easier to recruit patients to the trial and may also be ethically desirable. Our results show that this can be done with very little if any reduction in expected net benefit.