Clinical Trial Sample Size. The probability that a clinical trial will have a significantpositive result that is have a p-valueof less than the specified significance levelusually 5. The sample size is highly correlated with the cost of operation and the precision of your clinical evidence.
One of the key aspects of this protocol is sample size estimation. For an example consider a trial of an intervention to reduce the proportion of births by Caesarean section. It is used by Biostatisticians of all levels of expertise.
What are the risks of reducing sample size in clinical trials.
In 2017 90 of organizations with FDA approved clinical trials used nQuery as their sample size calculator. In brief we outline the basic steps for calculating sample size at the design stage of a clinical study. The calculation again shows that a sample size of 90 is required in each group. It is shown that as the size of the population N or expected size N in the case of geometric discounting becomes large the optimal trial size is O N12 or O N12.
