Canadian Journal of Anaesthesia

, Volume 43, Issue 2, pp 184–191 | Cite as

Study design in clinical research: sample size estimation and power analysis

  • Jerrold LermanEmail author


The purpose of this review is to describe the statistical methods available to determine sample size and power analysis in clinical trials. The information was obtained from standard textbooks and personal experience. Equations are provided for the calculations and suggestions are made for the use of power tables. It is concluded that sample size calculations and power analysis can be performed with the information provided and that the validity of clinical investigation would be improved by greater use of such analyses.

Key words

statistics: sample size calculation, power analysis 


Cet article de revue décrit les méthodes statistiques utilisées au cours des épreuves cliniques pour déterminer la taille d’un échantillon et l’analyse de sa puissance. L’information provient des manuels standards et de l’expérience de l’auteur. Des équations sont fournies avec des suggestions sur l’usage des tables de puissance. En conclusion, avec cette information, il est possible d’effectuer les calculs de la taille d’un échantillon et l’analyse de sa puissance; ces analyses amélioreraient la validité d’une étude clinique si on les utilisaient plus.


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Copyright information

© Canadian Anesthesiologists 1996

Authors and Affiliations

  1. 1.Department of Anaesthesia and the Research InstituteThe Hospital for Sick Children and University of TorontoTorontoCanada

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