TABLE 2.

Sensitivity, specificity, and predictive values

Method	Sensitivity (%)	Specificity (%)	Positive predictive value (%)	Negative predictive value (%)
ELISA alonea	82.4	100.0	100.0	99.4
ELISA-RA
All EHECa	76.5	100.0	100.0	99.2
O157b	100.0	100.0	100.0	100.0
SMAC
All EHECa	23.5	100.0	100.0	97.3
O157b	50.0	100.0	100.0	99.2

^an = 488. 

^bn = 479 (the three PCR-positive–culture-negative samples and the six non-O157:H7 culture-positive samples were deleted from this data set).