Sample size determination as an important statistical concept in Medical research

Abstract

Sample size is one of the important considerations at the planning phase of medical research, but researchers are often faced with difficulties of calculating valid sample size. Many researchers frequently use inadequate sample size and this invariably introduces errors into the final findings. Many reviews on sample size estimation have focused more on specific study designs which often present technical equations and formula that are boring to statistically naïve medical researchers. Hence, this paper reviews on sample size estimation formula may provide basic understanding and principles to achieve valid sample size estimation.