Biomaterial Database

Power and sample size for testing homogeneity of relative risks in prospective studies. 1999

J M Nam

Biostatistics Branch, National Cancer Institute, Rockville, Maryland 20892-7368, USA. namj@epndce.nci.nih.gov

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.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D011446	Prospective Studies	Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.	Prospective Study,Studies, Prospective,Study, Prospective
D003276	Contraceptives, Oral	Compounds, usually hormonal, taken orally in order to block ovulation and prevent the occurrence of pregnancy. The hormones are generally estrogen or progesterone or both.	Low-Dose Oral Contraceptive,Oral Contraceptive,Oral Contraceptives,Oral Contraceptives, Low-Dose,Oral Contraceptives, Phasic,Contraceptive, Low-Dose Oral,Contraceptive, Oral,Contraceptives, Low-Dose Oral,Contraceptives, Phasic Oral,Low Dose Oral Contraceptive,Low-Dose Oral Contraceptives,Oral Contraceptive, Low-Dose,Oral Contraceptives, Low Dose,Phasic Oral Contraceptives
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001437	Bacteriuria	The presence of bacteria in the urine which is normally bacteria-free. These bacteria are from the URINARY TRACT and are not contaminants of the surrounding tissues. Bacteriuria can be symptomatic or asymptomatic. Significant bacteriuria is an indicator of urinary tract infection.	Bacteriurias
D001699	Biometry	The use of statistical and mathematical methods to analyze biological observations and phenomena.	Biometric Analysis,Biometrics,Analyses, Biometric,Analysis, Biometric,Biometric Analyses
D012306	Risk	The probability that an event will occur. It encompasses a variety of measures of the probability of a generally unfavorable outcome.	Relative Risk,Relative Risks,Risk, Relative,Risks,Risks, Relative
D015197	Carcinogenicity Tests	Tests to experimentally measure the tumor-producing/cancer cell-producing potency of an agent by administering the agent (e.g., benzanthracenes) and observing the quantity of tumors or the cell transformation developed over a given period of time. The carcinogenicity value is usually measured as milligrams of agent administered per tumor developed. Though this test differs from the DNA-repair and bacterial microsome MUTAGENICITY TESTS, researchers often attempt to correlate the finding of carcinogenicity values and mutagenicity values.	Tumorigenicity Tests,Carcinogen Tests,Carcinogenesis Tests,Carcinogenic Activity Tests,Carcinogenic Potency Tests,Carcinogen Test,Carcinogenesis Test,Carcinogenic Activity Test,Carcinogenic Potency Test,Carcinogenicity Test,Potency Test, Carcinogenic,Potency Tests, Carcinogenic,Test, Carcinogen,Test, Carcinogenesis,Test, Carcinogenic Activity,Test, Carcinogenic Potency,Test, Carcinogenicity,Test, Tumorigenicity,Tests, Carcinogen,Tests, Carcinogenesis,Tests, Carcinogenic Activity,Tests, Carcinogenic Potency,Tests, Carcinogenicity,Tests, Tumorigenicity,Tumorigenicity Test