Research article
Sample size requirements for case-control study designs
-
Correspondence: Michael D Edwardes michael.edwardes@clinepi.mcgill.ca
Division of Clinical Epidemiology, Royal Victoria Hospital, Montreal, Quebec, Canada
BMC Medical Research Methodology 2001, 1:11 doi:10.1186/1471-2288-1-11
Published: 19 November 2001Abstract
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.