The determination of an "adequate" sample size is an essential part of the statistical planning process. Depending on your type of non-interventional study design and your specific study objectives, there are different approaches for the planning of your sample size [...]
The mean value of numerical data is without a doubt the most commonly used statistical measure. Anyone who has a basic statistical background knows how to calculate the (arithmetic) mean. However, sometimes the median is used as an alternative to the mean. [...]
In this article we would like to address the question whether it is useful to perform statistical testing in the context of a NIS, as it is often requested by the sponsor, and why, if tests are performed, we should handle their results with caution.