Table 2.
Measures of performance of the BinaxNOW G6PD
| BinaxNOW G6PD | Formula | Quantitative assay | ||
|---|---|---|---|---|
| Deficient (a + c) | Normal (b + d) | Deficient (N = 11) | Normal (N = 345) | |
| Deficient | a | b | 6 | 0 |
| Normal | c | d | 5 | 345 |
| Prevalence (P) | (a + c)/(a + b + c + d) | 3% | ||
| Sensitivity (Sn) | a/(a + c) | 54.5% (95% CI = 23–83) | ||
| Specificity (Sp) | d/(b + d) | 100% (95% CI = 98–100) | ||
| Positive predicted value | (Sn × P)/(Sn × P) + [(100 – Sp) × (100 – P)] | 100% (95% CI = 42–100) | ||
| Negative predictive value | Sp × (100 – P)/[(100 – Sn) × P] + [Sp × (100 – P)] | 99% (95% CI = 97–100) | ||
| Positive likelihood ratio | Sensitivity/(100 – specificity) | ∞ | ||
| Negative likelihood ratio | (100 – sensitivity)/specificity | 0.45 (95% CI = 0.24–0.87) | ||