title: Power and sample size for testing homogeneity of relative risks in prospective studies.
abstract: Power and sample-size formulas for testing the homogeneity of relative risks using the score method are presented. The homogeneity score test (Gart, 1985, Biometrika 72, 673-677) is formally equivalent to the Pearson chi-square test, although they look different. Results of this paper may be useful in assessing the validity of the model of a common relative risk before combining several 2 x 2 tables or in designing a prospective study for detecting heterogeneity of relative risks.
authors.affiliation: Biostatistics Branch, National Cancer Institute, Rockville, Maryland 20892-7368, USA. namj@epndce.nci.nih.gov
authors.forename: J M
authors.initials: JM
authors.lastname: Nam
mesh_terms: D000818:Animals; D001437:Bacteriuria / Q000209:etiology; D001699:Biometry; D015197:Carcinogenicity Tests / Q000706:statistics & numerical data; D003276:Contraceptives, Oral / Q000009:adverse effects; D005260:Female; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D051379:Mice; D015233:Models, Statistical; D011446:Prospective Studies; D012306:Risk; D018401:Sample Size
chemical_list: D003276:Contraceptives, Oral