Skip to main content
. Author manuscript; available in PMC: 2020 Apr 1.
Published in final edited form as: Sex Transm Dis. 2019 Apr;46(4):e38–e41. doi: 10.1097/OLQ.0000000000000938

Table 1.

2 × 2 contingency tables and performance characteristics of four algorithms (including outside cases) for the identification of incident syphilis among HIV-positive men who have sex with men, Boston, MA, 2016–2017.

Algorithm A Algorithm B
Chart review
Chart review
Algorithm Positive Negative Total Algorithm Positive Negative Total
Positive 150 5 155 Positive 157 6 163
Negative 52 1518 1570 Negative 45 1517 1562
Total 202 1523 1725 Total 202 1523 1725

Sens, % Spec, % PPV, % NPV, % Sens, % Spec, % PPV, % NPV, %
74.2 99.7 96.8 96.7 77.7 99.6 96.3 97.1

Algorithm C Algorithm D

Chart review
Chart review
Algorithm Positive Negative Total Algorithm Positive Negative Total
Positive 166 4 170 Positive 169 5 174
Negative 36 1520 1556 Negative 33 1518 1551
Total 202 1524 1726 Total 202 1523 1725

Sens, % Spec, % PPV, % NPV, % Sens, % Spec, % PPV, % NPV, %
82.2 99.7 97.6 97.7 83.7 99.7 97.1 97.9

NPV, negative predictive value; PPV, positive predictive value; RPR, rapid plama reagin; sens, sensitivity; spec, specificity