Design And Determination Of The Sample Size In Medical Research

Abstract

This paper is designed as a tool that a researcher could use in planning and conducting quality research. This is a review paper which gives a discussion of various aspects of designing consideration in medical research. This paper covers the essentials in calculating power and sample size for a variety of applied study designs. Sample size computation for survey type of studies, observation studies and experimental studies based on means and proportions or rates, sensitivity-specificity tests for assessing the categorical outcome are presented in detail. Over the last decades, considerable interest has been focused on medical research designs and sample size estimation. The resulting literature is scattered over many textbooks and journals. This paper presents these methods in a single review and comments on their application in practice.