Accommodating Measurements Below a Limit of Detection: A Novel Application of Cox Regression
Accommodating Measurements Below a Limit of Detection: A Novel Application of Cox Regression
In environmental epidemiology, measurements of exposure biomarkers often fall below the assay's limit of detection. Existing methods for handling this problem, including deletion, substitution, parametric regression, and multiple imputation, can perform poorly if the proportion of “nondetects” is high or parametric models are misspecified. We propose an approach that treats …