Table 4.

Test performance and number of COVID-19 false positives per 10,000 population tested, for varied test specificities and disease prevalence (given a sensitivity of 99.9%)

Prevalence	Specificity	PPV	False positive rate	Number with disease in population per 10,000 tested	Number of false positives per 10,000 tested
0.0005	0.999	33.32%	0.1%	5	10
0.0005	0.95	0.99%	5.0%	5	500
0.0005	0.9	0.50%	10.0%	5	1000
0.0005	0.8	0.25%	20.0%	5	2000
0.0005	0.7	0.17%	30.0%	5	3000
0.001	0.999	50.00%	0.1%	10	10
0.001	0.95	1.96%	5.0%	10	500
0.001	0.9	0.99%	10.0%	10	1000
0.001	0.8	0.50%	20.0%	10	2000
0.001	0.7	0.33%	30.0%	10	3000
0.01	0.999	90.98%	0.1%	100	10
0.01	0.95	16.79%	5.0%	100	500
0.01	0.9	9.17%	10.0%	100	1000
0.01	0.8	4.80%	20.0%	100	2000
0.01	0.7	3.25%	30.0%	100	3000
0.03	0.999	96.86%	0.1%	300	10
0.03	0.95	38.19%	5.0%	300	500
0.03	0.9	23.60%	10.0%	300	1000
0.03	0.8	13.38%	20.0%	300	2000
0.03	0.7	9.34%	30.0%	300	3000