Assessing the role of undetected colonization and isolation precautions in reducing Methicillin-Resistant Staphylococcus aureus transmission in intensive care units

BMC Infectious Diseases

Table 5 Two measures of nares test sensitivity based upon serial nares cultures

Ward	Sensitivity of Detecting Nares Colonization (%)^a	Sensitivity of detecting colonization at any body site (%): Median (95% CI)^b
M1	92	64 (56, 71)
M2	84	56 (47, 65)
GS1	82	61 (54, 69)
GS2	88	50 (42, 57)
SS1	89	62 (54, 68)
SS2	89	68 (60, 76)
SS3	85	55 (45, 64)
SS4	72	54 (44, 65)
Overall	85	59 (55, 63)

^a Given by the ratio TP/(TP+FN) where TP is the number of positive swabs excluding the first for each patient episode and FN the number of negative swabs that follow an earlier positive for the same patient.
^b The parameter p estimated from the model making use of cultures from all sites.