Relation between presence of extended-spectrum β-lactamase-producing Enterobacteriaceae in systematic rectal swabs and respiratory tract specimens in ICU patients

Annals of Intensive Care

Table 3 Sensitivity, specificity, positive predictive value, negative predictive value and likelihood ratios of digestive colonization for extended-spectrum β-lactamase-producing Enterobacteriaceae in respiratory sample

Variable	Early group (≤5 days) (n = 1557)	Late group (>5 days) (n = 941)
Sensitivity (%) [95% CI]	75.6% [73.4–77.7]	75.3% [72.6–78.1]
Specificity (%) [95% CI]	86.8% [85.1–88.5]	71.0% [68.1–73.9]
Positive predictive value (%) [95% CI]	14.5% [12.8–16.3]	34.4% [31.4–37.4]
Negative predictive value (%) [95% CI]	99.2% [98.7–99.6]	93.4% [91.9–95.0]
Positive LR [95% CI]	5.71 [4.63–7.05]	2.60 [2.26–2.99]
Negative LR [95% CI]	0.28 [0.17–0.47]	0.35 [0.26–0.46]

LR likelihood ratio. Sensitivity, specificity, positive predictive value, negative predictive values are expressed as percentage [95% CI]. Likelihood ratios are expressed as absolute value [95% CI]