A simple computerized program for the calculation of the required sample size necessary to ensure statistical accuracy in medical experiments

We developed a sample size estimation program (SSEP) with which medical res earchers can easily estimate the appropriate sample size for a specific sig nificance level and statistical power using their favorite WWW browsers. SS EP can estimate the sample sizes for six statistical methods by Monte-Carlo simulation: Student's I-test, Welch's t-test, Analysis of valiance, Wilcox on's rank sum test, Kruskal-Wallis test, and the Cochran-Armitage test for linear trends. The SSEP simulation programs were created using the SAS soft ware macro language. Medical researchers can interactively use this program and determine reliable sample sizes when planning new prospective clinical studies and animal experiments. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.