Testing Claimed Minimal Detectable Concentrations of in Vitro Medical Diagnostic Devices

Abstract

Abstract Manufacturers and users of medical diagnostic devices are provided a statistical decision tool for investigating a claimed minimal detectable concentration (MDC). The MDC is defined by setting two respective probabilities: that the blank sample being analyzed is determined to have analyte and that the device fails to determine a low concentration of analyte at the MDC. The statistical procedure for simultaneously testing the two aforementioned analytical decision errors assumes that signal responses follow a gaussian distribution but does not require a fitted calibration curve, knowledge of distribution parameters, or the assumption of constant variance in the low assay range. Evaluation of the operating characteristics of the procedure requires knowledge only of the variance ratio between the MDC and zero-dose signal distributions, which usually is well known.