Table 2.

Definitions of measures of report accuracy^*

Identified in any of the confirmation sources	Report of cancer by respondent
	Present	Absent
Yes	TP	FN	Sensitivity = TP/TP + FN
No	FP	TN	Specificity = TN/TN + FP
	PPV = TP/TP + FP	NPV = TN/TN + FN

^*FN = false negative; FP = false positive; NPV  = negative predictive value; PPV  = positive predictive value; TN = true negative; TP = true positive.