The reactivity threshold (Figure) is used to categorize a serum as reactive or nonreactive and to determine the diagnostic sensitivity (DSN) and diagnostic specificity
(DSP) of the assay.
Graeme Eisenhofer: For borderline test results, it is important that follow-up tests have at least equal diagnostic sensitivity and, ideally, better diagnostic specificity
than the initial screening test.
In contrast, the high diagnostic specificity
indicates that the TMPRSS2-ERG gene fusion could be used as a noninvasive adjunct marker in urine, in combination with other markers such as PSA and PCA3, to improve overall diagnostic accuracy (11).
Diagnostic sensitivity, 100 X [TP/(TP + FN)]; diagnostic specificity
, 100 X [TN/(TN + FP)]; and efficiency, 100 X [(TP + TN)/(TP + TN + FP + FN)] were calculated at multiple screening and confirmation cutoffs.
Methylated markers BMP3, NDRG4, VIM, and TFPI2, respectively, detected 84%, 92%, 86%, and 92% of colorectal cancers and 68%, 76%, 76%, and 88% of advanced adenomas at a diagnostic specificity
cutoff of 95%.
In the study reported here, we compared the diagnostic sensitivity and diagnostic specificity
of serum creatinine and Cys for early CIN prediction in a population of patients undergoing coronary angiography and interventions who were at risk for AKI.
Percentages for samples from individuals exceeding the various cutoffs, diagnostic sensitivity, diagnostic specificity
, positive predictive value, and negative predictive value (with 95% CIs) were calculated for the combined serious outcome (death, MI, heart failure, serious arrhythmia, refractory ischemic cardiac pain).
John Blackwood: The challenge is to demonstrate an adequate level of diagnostic specificity
at the 99th-percentile upper reference limit.