Table 3.

Relationship between test performance, PPV, and NPV for asymptomatic people

	Predictive values		Distribution of test outcomes among 10 000 people tested
	PPV	NPV	True positive	False positive	True negative	False negative
5% likelihood of testing positive
80% sensitivity, 97% specificity	58%	99%	400	285*	9215	100
80% sensitivity, 98% specificity	68%	99%	400	190*	9310	100
80% sensitivity, 99% specificity	81%	99%	400	95*	9405	100
90% sensitivity, 99% specificity	83%	99%	450	95*	9405	50
10% likelihood of testing positive
80% sensitivity, 97% specificity	75%	98%	800	270*	8730	200
80% sensitivity, 98% specificity	82%	98%	800	180*	8820	200
80% sensitivity, 99% specificity	90%	98%	800	90	8910	200
90% sensitivity, 99% specificity	91%	99%	900	90	8910	100

People at higher risk of acquiring or transmitting COVID-19 than the general population such as health-care workers, care home workers, and first responders. NPV=negative predictive value. PPV=positive predictive value.

^*Mitigation strategy is to confirm positives.