SAMPLE SIZE DETERMINATION IN ANIMAL HEALTH STUDIES

Abstract

One of the most important factors to consider in the design of an intervention trial is the choice of an appropriate study size. Studies that are too small may fail to detect important effects on the outcomes of interest, or may estimate those effects too imprecisely. Studies that are larger than necessary are a waste of resources. Statistical methods are available for estimation of appropriate sample size depending upon the type of outcome measure, expected disease rates or size of effects, study design and the requirements of confidence interval/precision or power. These concepts along with the methods of estimating sample size in varied situations are presented in this article. Key