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
Do you have an account?
- Rent for 48h to view
- Buy Cloud Access for unlimited viewing via different devices
- Synchronizing in the ReadCube Cloud
- Printing and saving restrictions apply
Rental: USD 8.50
Cloud: USD 20.00
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.
© 2001 S. Karger AG, Basel
- Morton NE, Collins A: Tests and estimates of allelic association in complex inheritance. Proc Natl Acad Sci USA 1998;95:11389–11393.
- Sasieni PD: From genotypes to genes: Doubling the sample size. Biometrics 1997;53:1253–1261.
Armitage P: Tests for linear trends in proportions and frequencies. Biometrics 1955;11:375–386.
- Devlin B, Roeder K: Genomic control for association studies. Biometrics 1999;55:997–1004.
Nam J: A simple approximation for calculating sample sizes for detecting linear trend in proportions. Biometrics 1987;43:701–705.
- Risch NJ: Searching for genetic determinants in the new millennium. Nature 2000;405:847–856.
- Wacholder S, Rothman N, Caporaso N: Population stratification in epidemiologic studies of common genetic variants and cancer: Quantification of bias. J Natl Cancer Inst 2000;92:1151–1158.
Article / Publication Details
Copyright / Drug Dosage / DisclaimerCopyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.