Table 1.

Key statistical terminology in the context of population screening tests for ovarian cancer

Characteristic	Synonyms	Definition
Prevalence	Pre-test probability	Proportion of population affected by a condition
Sensitivity	Detection rate; True positive rate (TPR)	Proportion of subjects with cancer who test positive
Specificity	True negative rate (TNR)	Proportion of subjects without cancer who test negative
False positive rate (FPR)	1 - specificity; Type I Error; α	Proportion of subjects without cancer who test positive
False negative rate (FNR)	1 - sensitivity, Type II error; β	Proportion of subjects with cancer who test negative
Positive Predictive Value (PPV)	Positive post-test probability	Probability that a subject with a positive test has cancer
Negative Predictive Value (NPV)	Negative post-test probability	Probability that a subject with a negative test does not have cancer
Positive likelihood ratio (LR+)	TPR / FPR	Ratio between the probability of a positive test result given the presence of the disease and the probability of a positive test result given the absence of the disease
Negative likelihood ratio (LR-)	1 – TPR / specificity	Ratio between the probability of a negative test result given the presence of the disease and the probability of a negative test result given the absence of the disease
Odds Ratio	[TPR / (1 − TPR)] × [(1 − FPR) / FPR]
Receiver-Operating Characteristic (ROC) Curve		Plot of sensitivity vs. FPR
Area under the ROC Curve (AUC)	C-statistic	A normalized Mann Whitney/Wilcoxon test where the Wilcoxon statistic is divided by the product of the number of individuals in the two groups measured
Accuracy		Overall probability that a subject will be correctly classified