TABLE 2.

Performance of direct ICS test in retrospective study using stored specimens

ICS test result	No. of specimens whose result by culturec was:
	Positive		Negative
	No CBa	In CBb	No CB	In CB
Positive (no. of specimens)	328	11	5	0
Negative (no. of specimens)	74	4	77	21
Sensitivity (%)d	82	77	NAe	NA
Specificity (%)	NA	NA	94	100

^aSpecimens frozen without transport medium (Cary-Blair [CB] medium). 

^bSpecimens preserved in Cary-Blair (CB) medium. 

^cE. coli O157:H7 culture. 

^dNo significant difference between values for culture-positive specimens (P > 0.05, χ² test). 

^eNA, not applicable.