Case-Control Studies of Genetic Markers: Power and Sample Size Approximations for Armitage’s Test for TrendSlager S.L. · Schaid D.J.
Department of Health Sciences Research, Mayo Clinic, Rochester, Minn., USA
The association of a candidate gene with disease can be efficiently evaluated by a case-control study in which allele frequencies are compared for diseased cases and unaffected controls. However, when the distribution of genotypes in the population deviates from Hardy-Weinberg proportions, the frequency of genotypes – rather than alleles – should be compared by the Armitage test for trend. We present formulas for power and sample size for studies that use Armitage’s trend test. The formulas make no assumptions about Hardy-Weinberg equilibrium, but do assume random ascertainment of cases and controls, all of whom are independent of one another. We demonstrate the accuracy of the formulas by simulations.
Copyright © 2001 S. Karger AG, Basel
Susan Slager, PhD
Department of Health Sciences Research
Mayo Clinic, Rochester, MN 55905 (USA)
Fax +1 507 284 1516, E-Mail email@example.com
Received: Received: November 8, 2000
Accepted: January 3, 2001
Revision received: January 2, 2001
Number of Print Pages : 5
Number of Figures : 1, Number of Tables : 2, Number of References : 7
Human Heredity (International Journal of Human and Medical Genetics)
Founded 1950 as Acta Genetica et Statistica Medica by Gunnar Dahlberg; Continued by M. Hauge (1965–1983)
Vol. 52, No. 3, Year 2001 (Cover Date: Released September 2001)
Journal Editor: J. Ott, New York, N.Y.
ISSN: 0001–5652 (print), 1423–0062 (Online)
For additional information: http://www.karger.ch/journals/hhe