An introduction to design of clinical studies

Clinical research is broadly divided into observational and experimental studies. Both types will be divided in more detail and supported with examples from medicine.

One of the very important components in the design of most clinical research is the calculation of sample size. If too few patients, it is unlikely that we will be able to distinguish the real clinical impact of random variation in the sample, a very large sample however (in addition to the waste of medical tests) can also mean that more patients are treated less effectively than they would be otherwise.

We will inspect of what is needed and be known to be able to calculate a clinical trial sample size. This will be illustrated with an example.