title: Calculating sample size bounds for logistic regression.
abstract: The calculation of a study's required sample size is one of the most important aspects of the validity of an epidemiological study. Logistic regression often is used in modelling in epidemiology. A simplified method to calculate the sample size for the multiple logistic-regression model was proposed by Hsieh et al. [Stat. Med. 17 (1998) 1623]. The approach for estimating the sample size is described and then applied in the planning of an epidemiological cross-sectional study of the associations of different risk factors with Toxoplasma infection among pregnant women. Although the method demands some additional information which is often difficult to obtain, it is a very useful tool in veterinary epidemiology.
authors.affiliation: WHO-Collaborating Centre for Research and Training in Veterinary Public Health, School of Veterinary Medicine Hannover, Bünteweg 2, D-30559 Hannover, Germany. susanne.broll@tiho-hannover.de
authors.forename: Susanne
authors.initials: S
authors.lastname: Broll
authors.forename: Sabine
authors.initials: S
authors.lastname: Glaser
authors.forename: Lothar
authors.initials: L
authors.lastname: Kreienbrock
mesh_terms: D000818:Animals; D003430:Cross-Sectional Studies; D004812:Epidemiologic Methods / Q000662:veterinary*; D005260:Female; D006801:Humans; D016015:Logistic Models; D016017:Odds Ratio; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000453:epidemiology / Q000276:immunology; D015203:Reproducibility of Results; D012307:Risk Factors; D018401:Sample Size; D016036:Seroepidemiologic Studies; D014122:Toxoplasma / Q000276:immunology; D014123:Toxoplasmosis / Q000453:epidemiology / Q000276:immunology