Table 2

Operator-based interview performances

Time interval
(prevalence range)
rtPCR+rtPCR−
Whole training set
(73–1579 per 100 000 people)
 Suspected cases, n50 98084 897 37.5% PPV
 Not suspected cases, n8618120 553 93.3% NPV
85.5%* 58.7%
Q1
(73–290 per 100 000 people)
 Suspected cases, n130217 461 6.9% PPV
 Not suspected cases, n46337 518 98.8% NPV
73.8%* 68.2%
Q2
(306–542 per 100 000 people)
 Suspected cases, n922724 040 27.7% PPV
 Not suspected cases, n166531 230 94.9% NPV
84.7%* 56.5%
Q3
(543–815 per 100 000 people)
 Suspected cases, n14 43223 355 38.2% PPV
 Not suspected cases, n252829 249 92.0% NPV
85.1%* 55.6%
Q4
(823–1579 per 100 000 people)
 Suspected cases, n28 66721 488 57.2% PPV
 Not suspected cases, n417525 438 85.9% NPV
87.3%* 54.2%
  • *Sensitivity.

  • †Specificity.

  • Q, quartile; rtPCR, reverse transcriptase PCR; PPV, positive predictive value; NPV, negative predictive value.