The just-about-right pilot sample size to control the error margin

Obodo, Scholastica; Toher, Deirdre; White, Paul

Abstract

In practice, the required sample size for a two-arm randomised controlled trial cannot always be determined pre-study with great accuracy. This lack of accuracy has economic, ethical and scientific implications. The sample size for a pilot study is an important consideration in helping the decision making for the sample size of a follow-on trial. Consideration of under- and over-estimation of the sample size results in the idea of a Just-About-Right (JAR) sample size. For studies involving a minimally clinical important difference (MCID) we present the pilot sample sizes to meet investigator desired JAR considerations.

• Journal Article Type: Article
• Acceptance Date: Apr 17, 2023
• Online Publication Date: May 23, 2023
• Publication Date: May 23, 2023
• Deposit Date: Apr 19, 2023
• Publicly Available Date: Sep 28, 2023
• Journal: International Journal of Statistics and Probability
• Print ISSN: 1927-7032
• Electronic ISSN: 1927-7040
• Publisher: Canadian Center of Science and Education
• Peer Reviewed: Peer Reviewed
• Volume: 12
• Issue: 3
• DOI: https://doi.org/10.5539/ijsp.v12n3p1
• Keywords: Sample size, error margin, Just-About-Right, overestimation, Pilot study, power, Sample size, underestimation
• Public URL: https://uwe-repository.worktribe.com/output/10635540
• Publisher URL: https://www.ccsenet.org/journal/index.php/ijsp