A correction for this article has been published in BMC Medical Research Methodology 2002, 2:16

Research article

Sample size requirements for case-control study designs

Michael D Edwardes

Division of Clinical Epidemiology, Royal Victoria Hospital, Montreal, Quebec, Canada

author email corresponding author email

BMC Medical Research Methodology 2001, 1:11doi:10.1186/1471-2288-1-11

Published:	19 November 2001

Abstract

Background

Published formulas for case-control designs provide sample sizes required to determine that a given disease-exposure odds ratio is significantly different from one, adjusting for a potential confounder and possible interaction.

Results

The formulas are extended from one control per case to F controls per case and adjusted for a potential multi-category confounder in unmatched or matched designs. Interactive FORTRAN programs are described which compute the formulas. The effect of potential disease-exposure-confounder interaction may be explored.

Conclusions

Software is now available for computing adjusted sample sizes for case-control designs.