WOLFRAM|DEMONSTRATIONS PROJECT

Calculator for Diagnostic Accuracy Measures

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nondiseased population
negative test result
8550
positive test result
950
diseased population
positive test result
450
negative test result
50
population statistics
total population
10000
nondiseased
9500
diseased
500
prevalence of disease
0.050000
diagnostic accuracy measures of the test
sensitivity
0.900000
specificity
0.900000
positive predictive value
0.321429
negative predictive value
0.994186
odds ratio
81.000000
likelihood ratio for a positive result
9.000000
likelihood ratio for a negative result
0.111111
This Demonstration calculates various accuracy measures of a diagnostic test for a disease. This is done for differing negative and positive test results of nondiseased and diseased populations. The measures calculated are the positive predictive value ("PPV"), the negative predictive value ("NPV"), the (diagnostic) odds ratio ("OR"), the likelihood ratio for a positive test result ("LR+"), and the likelihood ratio for a negative test result ("LR-"). The negative and positive test results of the nondiseased and diseased populations are selected using the sliders.