Practical aspects regarding sample size in clinical research
Vega Ramos, B.; Peraza Yanes, O.; Herrera Correa, G.; Saldívar Toraya, S.
Revista de Gastroenterologia de Mexico 61(3): 246-251
1996
ISSN/ISBN: 0375-0906 PMID: 9102749 Document Number: 466339
The knowledge of the right sample size let us to be sure if the published results in medical papers had a suitable design and a proper conclusion according to the statistics analysis. To estimate the sample size we must consider the type I error, type II error, variance, the size of the effect, significance and power of the test. To decide what kind of mathematics formula will be used, we must define what kind of study we have, it means if its a prevalence study, a means values one or a comparative one. In this paper we explain some basic topics of statistics and we describe four simple samples of estimation of sample size.