Author Description

Determining an appropriate sample size is a necessary step in any statistical design of scientific studies such as clinical trials, medical investigations, and animal laboratory experiments. There are a number of challenges faced by practitioners—ethical, methodological, and economic—to establish appropriate sample sizes for various clinical trials, which is the focus of this work. Illustrating the usefulness of several commonly used parametric distributions through numerous examples from the medical and health sciences, the authors examine sample size determination using three basic approaches: * The "point estimation approach” is used to determine the required sample size by controlling the variation of the point estimate to the desired accuracy. * The "interval estimation approach” is used to determine the required sample size by controlling the width of the confidence interval with a specified confidence level. * The "significance testing approach” is used to determine the required sample size by controlling the power of a significance test with a specified level of significance. Key features of the work: * All sample size calculations are driven by practical examples from the medical and health sciences. * Explicit sample size computation formulae are provided. * Methods are illustrated through many examples, illustrations, and tables. Sample Size Determination will be a useful reference for researchers and practitioners in the medical and health sciences, as well as senior undergraduate and graduate students in these areas. The work may be used in graduate courses on sampling theory, biostatistics, statistical methods in health research, and statistical inference.