Premium
Identifiability of Models for Multiple Diagnostic Testing in the Absence of a Gold Standard
Author(s) -
Jones Geoffrey,
Johnson Wesley O.,
Hanson Timothy E.,
Christensen Ronald
Publication year - 2010
Publication title -
biometrics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.298
H-Index - 130
eISSN - 1541-0420
pISSN - 0006-341X
DOI - 10.1111/j.1541-0420.2009.01330.x
Subject(s) - identifiability , multinomial distribution , gold standard (test) , econometrics , degrees of freedom (physics and chemistry) , test (biology) , population , biometrics , computer science , statistics , mathematics , artificial intelligence , medicine , biology , paleontology , physics , environmental health , quantum mechanics
Summary We discuss the issue of identifiability of models for multiple dichotomous diagnostic tests in the absence of a gold standard (GS) test. Data arise as multinomial or product‐multinomial counts depending upon the number of populations sampled. Models are generally posited in terms of population prevalences, test sensitivities and specificities, and test dependence terms. It is commonly believed that if the degrees of freedom in the data meet or exceed the number of parameters in a fitted model then the model is identifiable. Goodman (1974, Biometrika 61, 215–231) established that this was not the case a long time ago. We discuss currently available models for multiple tests and argue in favor of an extension of a model that was developed by Dendukuri and Joseph (2001, Biometrics 57, 158–167). Subsequently, we further develop Goodman's technique, and make geometric arguments to give further insight into the nature of models that lack identifiability. We present illustrations using simulated and real data.