Sample size calculation in biomedical, clinical and biological sciences research

Abstract Sample size determination is a critical aspect of biomedical research, as it dictates the number of samples needed for a successful experiment that can yield generalizable results to the broader population. This paper outlines the methodology for calculating sample sizes in various categories of biomedical and clinical research, encompassing cross-sectional surveys, comparative studies, case–control studies, cohort studies, and animal studies. Detailed examples are provided for each category. The determination of an appropriate sample size holds significant importance from scientific, ethical, and resource allocation perspectives. It is noteworthy that research outcomes are often directly influenced by the accuracy of sample size calculations. A robust sample size calculation serves as a cornerstone for researchers, enabling them to draw precise inferences with a high level of precision across a spectrum of biomedical and clinical investigations.