Evaluation of RNA Extraction-Free Method for Detection of SARS-CoV-2 in Salivary Samples for Mass Screening for COVID-19

Table 4

Compares the parameters between the BGI and Thermo Fisher kit.

Parameters	RNA extraction-free direct method (BGI) -258	RNA extraction-free direct method (Thermo) -258	value
Sensitivity	85.15	99.01	< 0.001
Specificity	92.06	89.65	0.674
PPV	91.59	98.52	< 0.001
NPV	85.92	92.86	0.317
Kappa agreement %	74.8	58.3	<0.001
Invalid results	4/258 (1.5%)	27/258 (10.5%)	<0.0001
False positive results	10/254 (3.9%)	3/231 (1.2%)	0.071