title: Sample size estimation and power analysis for clinical research studies.
abstract: Determining the optimal sample size for a study assures an adequate power to detect statistical significance. Hence, it is a critical step in the design of a planned research protocol. Using too many participants in a study is expensive and exposes more number of subjects to procedure. Similarly, if study is underpowered, it will be statistically inconclusive and may make the whole protocol a failure. This paper covers the essentials in calculating power and sample size for a variety of applied study designs. Sample size computation for single group mean, survey type of studies, 2 group studies based on means and proportions or rates, correlation studies and for case-control for assessing the categorical outcome are presented in detail.
authors.affiliation: Department of Biostatistics, National Institute of Animal Nutrition and Physiology, Bangalore, India.
authors.forename: Kp
authors.initials: K
authors.lastname: Suresh
authors.forename: S
authors.initials: S
authors.lastname: Chandrashekara