Correction of Verification Bias by Application of Homogeneous Log-Linear Models for a Single Binary-Scale Diagnostic Test

• Activity Number: 374
• Type: Contributed
• Date/Time: Tuesday, August 11, 2015 : 10:30 AM to 12:20 PM
• Sponsor: Section on Medical Devices and Diagnostics
• Author(s): Haresh Rochani* and Robert Vogel and Hani Samawi and JingJing Yin
• Companies: Georgia Southern University and Georgia Southern University and Georgia Southern University and Georgia Southern University
• Keywords: Diagnostic Tests ; Sensitivity ; Specificity ; Log-linear models ; Missing data ; Verification Bias

Abstract

In patient management and control of many infectious diseases it is very crucial to have accurate diagnostic test. The test/procedure that determines the true disease status without an error is referred to as gold standard test. Even when a gold standard exist, it is extremely difficult to verify each patient due to the issues of cost-effectiveness and invasive nature of the procedures. The ability of the diagnostic tests to correctly identify the patients with and without the disease can be evaluated by measures such as sensitivity, specificity and predictive values. However, these measures can give biased estimates if we only consider the patients with test results who underwent for gold standard procedure (Verification Bias). The emphasis of this research is to apply Baker, Rosenberger and Dersimonian (BRD) model approach to derive the maximum likelihood estimates and variances for sensitivity, specificity and predictive values by using homogenous log-linear models. We apply this approach to analyze Hepatic Scintigraph data under the assumption of ignorable as well as non-ignorable missing data mechanisms.