47 Addressing Varying Sample-Specific Sensitivity with a New Test for Binary Biomarker Identification

Oregon Convention Center 

MicroRNAs (miRNAs) are promising biomarker candidates for their association with a wide range of diseases and their presence in easy-to-obtain biofluids. Since many extracellular miRNAs have concentrations that are often below or near the limit of detection, it is more appropriate to evaluate them as binary biomarkers than as continuous or count variables. Similar to other technologies, the binary detection of a miRNA molecule is influenced by technical variations, which we refer to as the sample-specific sensitivity. We propose a new likelihood ratio test that accounts for the sample-specific sensitivity and compare it to a binomial test which assumes all samples having the same sensitivity equals one. We focus on the NanoString nCounter data as an example for estimating the sample-specific sensitivities by pooling information across all features. With simulations, we demonstrate that, when the sample qualities are not balanced between comparison groups, the proposed test remains valid with stronger statistical power and controlled false discovery rate. Additionally, we provide applications of the new test procedure to publicly available nCounter data sets from the GEO database.

Sample-Specific Sensitivity

Binary Biomarker

MicroRNA

NanoString nCounter

Statistical Test

Biomarker Identification 

Section on Statistics in Genomics and Genetics