Guidelines for Small Size Samples Biostatistics in Current Medical Practice

The present study aims at bringing useful guidelines to a physician for determining the sample size when designing any research project. The sample size is an estimate of the number of patients determined in concordance with the objectives and the budget of the project. This paper presents several ways for sample size determination i.e. classic methods, Bayesian approach, dedicated software. All of them are analyzed considering that the end-user is not a statistician, but a doctor and pointers for choosing the best way when dealing with a small SS are highlighted.