StATS: Justifying the sample size for a microarray study (August 9, 2007)

I'm helping out with a grant proposal that is using microarrays for part of the analysis. A microarray is system for quantitative measurement of circulating mRNA in human, animal, or plant tissue. A microarray will typically measure thousands or tens of thousands of different mRNA sequences. An important issue for this particular grant (and many grants involving microarray data) is how to justify the sample size. Here are a few references that I will use to develop such a justification.

Determination of minimum sample size and discriminatory expression patterns in microarray data. Daehee Hwang, William A. Schmitt, George Stephanopoulos and Gregory Stephanopoulos. Bioinformatics 2002: 18(9);  1184-1193. [Medline] [Abstract] [PDF]

Power and sample size for DNA microarray studies. Lee ML, Whitmore GA. Stat Med. 2002 Dec 15;21(23):3543-70. [Medline] [PDF]

False discovery rate, sensitivity and sample size for microarray studies. Pawitan Y, Michiels S, Koscielny S, Gusnanto A, Ploner A. Bioinformatics. 2005 Jul 1;21(13):3017-24. Epub 2005 Apr 19. [Medline] [Abstract] [Full text] [PDF]

Sample size determination in microarray experiments for class comparison and prognostic classification. Dobbin K, Simon R. Biostatistics. 2005 Jan;6(1):27-38. [Medline] [Abstract] [PDF]

Sample size for detecting differentially expressed genes in microarray experiments. Wei C, Li J, Bumgarner RE. BMC Genomics. 2004 Nov 8;5(1):87. doi:10.1186/1471-2164-5-87. [Medline] [Abstract] [Full text] [PDF]

Sample size for FDR-control in microarray data analysis. Jung SH. Bioinformatics. 2005 Jul 15;21(14):3097-104. Epub 2005 Apr 21. [Medline] [Abstract] [Full text] [PDF]

Another interesting paper appears in JASA (which is not an open source journal), but an earlier version is available on the web at

I will try to summarize one or more of these papers when I get the chance.

This page was written by Steve Simon while working at Children's Mercy Hospital. Although I do not hold the copyright for this material, I am reproducing it here as a service, as it is no longer available on the Children's Mercy Hospital website. Need more information? I have a page with general help resources. You can also browse for pages similar to this one at Category: Data mining or Category: Sample size justification.