Table 2.
Performance characteristics of Xpert in stool in comparison with culture and gastric aspirate Xpert standards
| Test | Reference standard | Number of patients included in evaluation | Sensitivity % (95% CI) | Specificity % (95% CI) | PPA (%) | NPA (%) | Kappa agreement (95% CI) |
|---|---|---|---|---|---|---|---|
| Stool Xpert | GA culture | 49 | 88.9 (50.7–99.4) | 95 (81.8–99.1) | 88.9 | 95 | 0.804 (0.592–1.00) |
| GA Xpert | 49 | 100 (62.9–100) | 95 (81.8–99.1) | 100 | 95 | 0.875 (0.706–1.00) | |
| GA Xpert | Stool Xpert | 49 | 81.8 (47.8–96.8) | 97.4 (84.6–99.9) | 81.8 | 97.3 | 0.818 (0.62–1.00) |
Sensitivity, specificity, 95% confidence intervals (CI), positive percent agreement (PPA), and negative percent agreement (NPA), and kappa scores were calculated in MS Excel