title: Optimal Allocation of Gold Standard Testing under Constrained Availability: Application to Assessment of HIV Treatment Failure.
abstract: The World Health Organization (WHO) guidelines for monitoring the effectiveness of HIV treatment in resource-limited settings (RLS) are mostly based on clinical and immunological markers (e.g., CD4 cell counts). Recent research indicates that the guidelines are inadequate and can result in high error rates. Viral load (VL) is considered the "gold standard", yet its widespread use is limited by cost and infrastructure. In this paper, we propose a diagnostic algorithm that uses information from routinely-collected clinical and immunological markers to guide a selective use of VL testing for diagnosing HIV treatment failure, under the assumption that VL testing is available only at a certain portion of patient visits. Our algorithm identifies the patient sub-population, such that the use of limited VL testing on them minimizes a pre-defined risk (e.g., misdiagnosis error rate). Diagnostic properties of our proposal algorithm are assessed by simulations. For illustration, data from the Miriam Hospital Immunology Clinic (RI, USA) are analyzed.
authors.affiliation: Assistant Professor, Department of Biostatistics, Center for Statistical Sciences, Brown University School of Public Health, Providence, RI 02912.
authors.forename: Tao
authors.initials: T
authors.lastname: Liu
authors.affiliation: Professor, Department of Biostatistics, Center for Statistical Sciences, Brown University School of Public Health, Providence, RI 02912.
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Hogan
authors.affiliation: Graduate Student, Department of Biostatistics, Center for Statistical Sciences, Brown University School of Public Health, Providence, RI 02912.
authors.forename: Lisa
authors.initials: L
authors.lastname: Wang
authors.affiliation: Statistical Programmer, Memorial Sloan-Kettering Cancer Center, New York City, NY 10016.
authors.forename: Shangxuan
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Associate Professor of Medicine, Division of Infectious Diseases, the Alpert Medical School of Brown University, Providence, RI 02912.
authors.forename: Rami
authors.initials: R
authors.lastname: Kantor
keywords: Antiretroviral failure; HIV/AIDS; ROC; constrained optimization; resource limited; tripartite classification