Sample size determination simplified: A review

Researchers active in clinical, epidemiological, or translational research have the aim to publish their outcomes so that they can generalize their findings to the population. The sample size decision should be based on the difference in the result between the two groups analyzed as in an analytical subject field. It should also be based on the acceptable P value for statistical significance and the expected statistical power to test a hypothesis. Therefore, the purpose of sample size planning is to calculate an appropriate number of subjects for a specified survey design. This article accounts the concepts in calculating the sample size.