Time interval (prevalence range) | rtPCR+ | rtPCR− | ||
Whole training set
(73–1579 per 100 000 people) | ||||
Suspected cases, n | 50 980 | 84 897 | 37.5% | PPV |
Not suspected cases, n | 8618 | 120 553 | 93.3% | NPV |
85.5%* | 58.7%† | |||
Q1
(73–290 per 100 000 people) | ||||
Suspected cases, n | 1302 | 17 461 | 6.9% | PPV |
Not suspected cases, n | 463 | 37 518 | 98.8% | NPV |
73.8%* | 68.2%† | |||
Q2
(306–542 per 100 000 people) | ||||
Suspected cases, n | 9227 | 24 040 | 27.7% | PPV |
Not suspected cases, n | 1665 | 31 230 | 94.9% | NPV |
84.7%* | 56.5%† | |||
Q3
(543–815 per 100 000 people) | ||||
Suspected cases, n | 14 432 | 23 355 | 38.2% | PPV |
Not suspected cases, n | 2528 | 29 249 | 92.0% | NPV |
85.1%* | 55.6%† | |||
Q4
(823–1579 per 100 000 people) | ||||
Suspected cases, n | 28 667 | 21 488 | 57.2% | PPV |
Not suspected cases, n | 4175 | 25 438 | 85.9% | NPV |
87.3%* | 54.2%† |
*Sensitivity.
†Specificity.
Q, quartile; rtPCR, reverse transcriptase PCR; PPV, positive predictive value; NPV, negative predictive value.