Table 3 Diagnostic accuracy of a rapid cryptococcal antigen lateral flow assay (CrAg LFA) on venous whole blood, fingerprick capillary blood, and urine for screening HIV-infected South African adults (N = 1,296).

From: Validation of clinic-based cryptococcal antigen lateral flow assay screening in HIV-infected adults in South Africa

 

#TP/(#TP + #FN)

Sensitivity% (95% CI)

#TN/ (#TN + #FP)

Specificity% (95% CI)

PPV% (95% CI)

NPV% (95% CI)

Positive LR(95% CI)

Negative LR(95% CI)

Clinic-based venous whole blood CrAg LFA

All participants

6/14

43 (18, 71)

1127/1149

98 (97, 99)

21 (12, 36)

99 (99, 100)

22.4 (10.8, 46.6)

0.58 (0.37, 0.92)

CD4 < 200 cells/mm3

6/13

46 (19, 75)

314/323

97 (95, 99)

40 (22, 61)

98 (96, 99)

16.6 (6.9, 39.6)

0.55 (0.33, 0.92)

CD4 < 100 cells/mm3

4/9

44 (14, 79)

140/147

95 (90, 98)

36 (17, 61)

97 (94, 98)

9.3 (3.3, 26.1)

0.58 (0.32, 1.1)

Clinic-based fingerprick capillary blood CrAg LFA

All participants

5/14

36 (13, 65)

1111/1149

97 (95, 98)

12 (6, 22)

99 (98, 99)

10.8 (5.0, 23.3)

0.66 (0.45, 0.98)

CD4 < 200 cells/mm3

5/13

38 (14, 68)

311/321

97 (94, 98)

33 (17, 56)

97 (96, 98)

12.4 (4.9, 31.0)

0.64 (0.41, 0.98)

CD4 < 100 cells/mm3

3/9

33 (7, 70)

141/147

96 (91, 98)

33 (13, 63)

96 (94, 97)

8.2 (2.4, 27.4)

0.70 (0.44, 1.1)

Clinic-based urine CrAg LFA

All participants

7/14

50 (23, 77)

1021/1137

90 (88, 91)

6 (3, 9)

99 (99, 100)

4.9 (2.8, 8.5)

0.56 (0.33, 0.94)

CD4 < 200 cells/mm3

7/13

54 (25, 81)

272/318

86 (81, 89)

13 (8, 21)

98 (96, 99)

3.7 (2.1, 6.6)

0.54 (0.30, 0.97)

CD4 < 100 cells/mm3

4/9

44 (14, 79)

115/144

80 (72, 86)

12 (6, 23)

96 (93, 98)

2.2 (0.99, 4.9)

0.70 (0.39, 1.3)

  1. CI = confidence interval; CrAg = cryptococcal antigen; EIA = enzyme immunoassay; FN = false negative; FP = false positive; LFA = lateral flow assay; LR = likelihood ratio; NPV = negative predictive value; PPV = positive predictive value; TN = true negative; TP = true positive.
Back to article page