San Francisco Bay Area Chapter of American Statistical Association
Time: 4:30 – 6:00 pm, May 25, 2017 (4:30-5:00 networking and light refreshment, 5:00-6:00 seminar)
Location: Building 303 Bay view conference room, Gilead 303 Velocity, Foster City, CA 94404 *Free parking* Please check in at the front desk.
Speaker: Dr. Xiaoli Qi Principal Member of Technical Staff, Tech Lead Oracle Corporation, Redwood Shores, CA
Title: Nonparametric calibration of two common susceptibility tests using interval-censored data with measurement error
Drug dilution (MIC) and disk diffusion (DIA) are the two common tests to determine pathogen susceptibility to antibiotics. In the drug dilution method, the classification breakpoints are concentrations and based directly on the pharmacokinetics and pharmacodynamics of the drug. For the disk diffusion method, these concentration breakpoints need to be converted into zone diameters. In this research, we've proposed a robust method of DIA breakpoint determination. Based on M-spline theory, we employ nonparametric density estimation and nonparametric monotone regression techniques to estimate the MIC density, the true MIC/DIA relationship, and the DIA breakpoints. Simulation studies have shown that this nonparametric method performs very well. Compared with the error-rate bounded method, the resulting DIA breakpoints are considerably more precise. This method could be applied to more general errors-in-variables model situations with and without interval censoring.