title: A unified approach to the analysis of case-distribution (case-only) studies.
abstract: A number of new study designs have appeared in which the exposure distribution of a case series is compared to an exposure distribution representing a complete theoretical population or distribution. These designs include the case-genotype study, the case-cross-over study, and the case-specular study. This paper describes a unified likelihood-based approach to the analysis of such studies, and discusses extensions of these methods when a control group is available. The approach clarifies certain assumptions implicit in the methods, and helps contrast these assumptions to those underlying ordinary case-control studies. There are several reasons to expect discrepancies between ordinary case-control estimates and case-distribution estimates; for example, case-distribution estimates can be more sensitive to exposure misclassification. Some discrepancies are illustrated in an application to case-specular data on wire codes and childhood cancer.
authors.affiliation: Department of Epidemiology, UCLA School of Public Health 90095-1772, USA.
authors.forename: S
authors.initials: S
authors.lastname: Greenland
mesh_terms: D016022:Case-Control Studies; D002648:Child; D018592:Cross-Over Studies; D004574:Electromagnetic Fields / Q000009:adverse effects*; D006801:Humans; D016013:Likelihood Functions; D009369:Neoplasms / Q000453:epidemiology / Q000209:etiology*; D012044:Regression Analysis