Table 1.
Gazelle-Multispectral screening sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) in comparison to reference standard methoda.
| Disease vs. Normalb |
Disease vs. Traitc |
Trait vs. Normald |
||||
|---|---|---|---|---|---|---|
| 0–3 Days | 4–28 Days | 0–3 Days | 4–28 Days | 0–3 Days | 4–28 Days | |
| True positive, TP | 2 | 0 | 2 | 0 | 36 | 1 |
| True negative, TN | 170 | 10 | 36 | 1 | 170 | 10 |
| False Positive, FP | 0 | 0 | 0 | 0 | 6 | 0 |
| False negative, FN | 0 | 0 | 0 | 0 | 1 | 0 |
| Sensitivity, TP/(TP + FN) | 100.0% | - | 100.0% | - | 97.3% | 100% |
| Specificity, TN/(TN + FP) | 100.0% | 100% | 100.0% | 100% | 96.6% | 100% |
| PPV, TP/(TP + FP) | 100.0% | - | 100.0% | - | 85.7% | 100% |
| NPV, TN/(TN + FN) | 100.0% | 100% | 100.0% | 100% | 99.4% | 100% |
a
216 and 11 ‘Valid’ tests out of 250 and 15 total tests for 0–3 days and 4–28 days subjects were included in this calculation. ‘Inconclusive’ tests did not generate a result that could be included in the sensitivity-specificity analysis [39, 40].
b
SS/SC/FS/FSC vs. AA/FA.
c
SS/SC/FS/FSC vs. AS/AC/FAS/FAC.
d
AS/AC/FAS/FAC vs. AA/FA, 6 subjects with Hb FA were recognized as Hb FAS, 1 subject with Hb FAS was recognized as Hb FA.