Author/Authors :
Pourhoseingholi، Mohamad Amin نويسنده Research Center for Gastroenterology and Liver Disease, Shahid Beheshti University of Medical Sciences, Tehran, Iran , , Vahedi، Mohsen نويسنده Gastroentrology and Liver Diseases Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran Vahedi, Mohsen , Rahimzadeh، Mitra نويسنده ,
Abstract :
Optimum sample size is an essential component of any research. The main purpose of the sample size calculation is to
determine the number of samples needed to detect significant changes in clinical parameters, treatment effects or
associations after data gathering. It is not uncommon for studies to be underpowered and thereby fail to detect the
existing treatment effects due to inadequate sample size. In this paper, we explain briefly the basic principles of sample
size calculations in medical studies.
