TABLE 2.

Overall diagnostic performance of RT-PCR and rapid antigen test performed on nasopharyngeal or salivary samples^a

Patient group	Diagnostic test	Prevalence (%)	Sensitivity [95% CI] (%)b	Specificity [95% CI] (%)	PPV [95% CI] (%)	NPV [95% CI] (%)
Health care workers (n = 453)	Nasopharyngeal RT-PCR	38	98 [94 to 99]	n.a.c	n.a.c	98 [96 to 99]
	Salivary RT-PCR	34	87 [81 to 91]	n.a.c	n.a.c	92 [89 to 95]
	Nasopharyngeal RAT	26	66 [59 to 73]	100 [98 to 100]	100 [97 to 100]	100 [78 to 86]
	Salivary RAT	1	2 [0.5 to 5]	99 [97 to 100]	60 [23 to 93]	61 [56 to 65]
Hospitalized patients (n = 22)	Nasopharyngeal RT-PCR	68	94 [72 to 99]	n.a.c	n.a.c	86 [49 to 99]
	Salivary RT-PCR	50	69 [44 to 86]	n.a.c	n.a.c	54 [28 to 79]
	Nasopharyngeal RAT	23	31 [14 to 56]	100 [61 to 100]	100 [57 to 100]	35 [17 to 59]
	Salivary RAT	4.5	6 [1 to 28]	100 [61 to 100]	100 [5 to 100]	29 [14 to 50]

^aCI, confidence interval; PPV, positive predictive value; NP, nasopharyngeal; NPV, negative predictive value, n.a., not applicable; RAT, rapid antigen testing; RT, reverse transcription.

^bDiagnostic performances were evaluated based on a composite outcome considering NP PCR and/or saliva PCR as a COVID-19 case.

^cCalculation of specificity and PPV is not applicable, since a positive NP PCR and/or saliva PCR are part of the definition of the composite outcome.