Table II.

Measures of diagnostic performance of ID NOW, compared with the reverse transcription polymerase chain reaction (RT-PCR) reference standard

A – 2x2 table
		RT-PCR result
		Positive	Negative	Total
	Positive	103	31	134
ID NOW result	Negative	21	5895	5916
	Total	124	5926	6050

B – Estimated diagnostic performance
Measurement	Diagnostic performance
Sensitivity	83.1% (103/124); CI 75.4–88.7
Specificity	99.5% (5895/5926); CI 99.3–99.6
Positive predictive value	76.9% (103/134); CI 69.0–83.2
Negative predictive value	99.6% (5895/5916); CI 99.5–99.8

CI, confidence interval.