TY - JOUR
T1 - A solution for the most basic optimization problem associated with an ROC curve
AU - Le, Chap T.
PY - 2006/12
Y1 - 2006/12
N2 - In a few cases, such as early pregnancy tests, the test results are dichotomous; many diagnostic tests, however, give results which are not binary. In the diagnosis of prostate cancer, prostate-specific antigen test result is on a continuous scale; or, in radiology, assessment of mammograms is on an ordinal scale. In such cases, the accuracy of the marker or test is often first summarized in a receiver operating characteristic (ROC) curve and then as the area under that curve. The area under the ROC curve, however, only shows the 'potential' of a marker; sooner or later, for practical uses, we still need to dichotomize the test result so that we can classify subjects as 'diseased' or 'healthy'. Finding an 'optimal' cutpoint to dichotomize a continuous marker is desirable and is a very basic problem but, in all or most cases, cutpoints used in practice are arbitrary. The difficulty lies in our failure to define and justify a criterion for optimality. In this paper, we will propose a solution by maximizing a well-known parameter - the Youden's Index - within the framework of the ROC curve.
AB - In a few cases, such as early pregnancy tests, the test results are dichotomous; many diagnostic tests, however, give results which are not binary. In the diagnosis of prostate cancer, prostate-specific antigen test result is on a continuous scale; or, in radiology, assessment of mammograms is on an ordinal scale. In such cases, the accuracy of the marker or test is often first summarized in a receiver operating characteristic (ROC) curve and then as the area under that curve. The area under the ROC curve, however, only shows the 'potential' of a marker; sooner or later, for practical uses, we still need to dichotomize the test result so that we can classify subjects as 'diseased' or 'healthy'. Finding an 'optimal' cutpoint to dichotomize a continuous marker is desirable and is a very basic problem but, in all or most cases, cutpoints used in practice are arbitrary. The difficulty lies in our failure to define and justify a criterion for optimality. In this paper, we will propose a solution by maximizing a well-known parameter - the Youden's Index - within the framework of the ROC curve.
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U2 - 10.1177/0962280206070637
DO - 10.1177/0962280206070637
M3 - Article
C2 - 17260924
AN - SCOPUS:33846200422
SN - 0962-2802
VL - 15
SP - 571
EP - 584
JO - Statistical methods in medical research
JF - Statistical methods in medical research
IS - 6
ER -