This study is (sadly) not available for free on the Internet
- but it is still worth highlighting here. Steven Julious provides some justification for the use of twelve patients per group in a pilot study. This is a useful starting point for discussion
- and it may serve as a useful lower bound. I would suggest that you consider the size of the larger trial that you are piloting. For a larger study that might require thousands or tens of thousands of patients
- a pilot study of 12 patients per group is woefully inadequate.
Sample size of 12 per group rule of thumb for a pilot study. Steven A. Julious. Pharmaceut. Statist. 2005; 4: 287–291. Abstract available at http://onlinelibrary.wiley.com/doi/10.1002/ps