Classification accuracy and cut point selection

Stat Med. 2012 Oct 15;31(23):2676-86. doi: 10.1002/sim.4509. Epub 2012 Feb 3.


In biomedical research and practice, quantitative tests or biomarkers are often used for diagnostic or screening purposes, with a cut point established on the quantitative measurement to aid binary classification. This paper introduces an alternative to the traditional methods based on the Youden index and the closest-to-(0, 1) criterion for threshold selection. A concordance probability evaluating the classification accuracy of a dichotomized measure is defined as an objective function of the possible cut point. A nonparametric approach is used to search for the optimal cut point maximizing the objective function. The procedure is shown to perform well in a simulation study. Using data from a real-world study of arsenic-induced skin lesions, we apply the method to a measure of blood arsenic levels, selecting a cut point to be used as a warning threshold.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Area Under Curve*
  • Arsenic / blood
  • Biomarkers / analysis*
  • Computer Simulation
  • Data Interpretation, Statistical*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Models, Statistical*
  • ROC Curve*
  • Skin Diseases / chemically induced


  • Biomarkers
  • Arsenic