A common problem for comparing the relative accuracy of two screening tests for Alzheimer’s disease (D) in a two-stage design study is verification bias. If the verification bias can be assumed to be ignorable, Zhou and Higgs (2000) have proposed a maximum likelihood approach to compare the relative accuracy of screening tests in a two-stage design study. However, if the verification mechanism also depends on the unobserved disease status, the ignorable assumption does not hold. In this paper, we discuss how to use a profile likelihood approach to compare the relative accuracy of two screening tests for AD without assuming the ignorable verification bias mechanism.
Clinical Epidemiology | Clinical Trials | Medical Specialties
Zhou, Xiao-Hua and Castelluccio, Pete, "Adjusting for Non-Ignorable Verification Bias in Clinical Studies for Alzheimer’s Disease" (July 2003). UW Biostatistics Working Paper Series. Working Paper 212.