The approach is based upon the loose site specificity (purine-5mC) of the cytosine methylation dependent restriction enzyme McrBC and, therefore, is capable of determining the regional DNA methylation density associated with the plurality of molecules present.
Receiver operating characteristics (ROC) curves were constructed based upon the sensitivity and specificity of the Q mci subtests.
The predictive validity of both instruments was compared using an optimal cut-off score of ≥2 for the RISC and ≥5 for the CFS, based upon the sensitivity and specificity, calculated a priori, from the ROC curves.
Correspondence between model-generated risk scores and observed mortality patterns was evaluated based upon the time-specific receiver operating characteristic (ROC) curve approach and definitions of incident sensitivity and dynamic specificity proposed by Heagerty and Zheng [ 58].
The cut-offs for statistical analysis were based upon the optimal sensitivity and specificity obtained from the Receiver operating curves as described [ 32].
Most of these results support the work of Olson and colleagues (4), although the fact that their system only detects small hemorrhages and microaneurysms is a serious limitation in our view, and sensitivity and specificity based upon the photographic interpretation by a single reader is unlikely to become widely accepted.
A new nomenclature for CYP74 enzymes, based upon the confirmed substrate and product specificities of recombinant proteins, has recently been proposed [ 8] and which assigns CYP74C to only HPLs with dual specificity.
Table 3 shows the sensitivity, specificity, positive predictive values (PPV) and negative predictive values (NPV) at defined cut-off values for each score based upon the best relationship between sensitivity and specificity.
Accordingly, we defined a priori our primary analysis to be based upon the narrowest window as it provided the greatest specificity and hence the least bias.
Sensitivity and specificity was determined at a gene level based upon the longest experimentally verified isoform of each gene.
