TABLE 3.
Combined diagnostic value of stools 1 and 2a
| Stool Xpert protocol | Parameter | Ratio (%; 95% CI) using indicated assay on 1st respiratory specimen as reference standard |
|
|---|---|---|---|
| Xpert | Culture | ||
| 0.6 g | n = 267b | n = 244c | |
| Sensitivity | 7/10 (70.0; 34.8–93.3) | 7/17 (41.2; 18.4–67.1) | |
| Specificity | 253/257 (98.4; 96.1–99.6) | 223/227 (98.2; 95.5–99.5) | |
| PPV | 7/11 (63.6; 30.8–89.1) | 7/11 (63.6; 30.8–89.1) | |
| NPV | 253/256 (98.8; 96.6–99.8) | 223/233 (95.7; 92.2–97.9) | |
| Swab | n = 270d | n = 247e | |
| Sensitivity | 5/10 (50.0; 18.7–81.3) | 6/17 (35.3; 14.2–61.7) | |
| Specificity | 258/260 (99.2; 97.2–99.9) | 229/230 (99.6; 97.6–100) | |
| PPV | 5/7 (71.4; 29.0–96.3) | 6/7 (85.7; 42.1–99.6) | |
| NPV | 258/263 (98.1; 95.6–99.4) | 229/240 (95.2; 91.6–97.6) | |
PPV, positive predictive value; NPV, negative predictive value; CI, confidence interval. The ratios are as follows: for sensitivity, number positive by stool 1 or 2 Xpert/number positive by reference assay; for specificity, number negative by stool 1 and 2 Xpert/number negative by reference assay; PPV, number positive by stool 1 or 2 Xpert which were also positive by reference assay/total number positive by stool 1 or 2 Xpert; NPV, number negative by stool 1 and 2 Xpert which were also negative by reference assay/total no. negative by stool 1 and 2 Xpert.
One child with only swab method on stool 1, 3 children with nondeterminate stool Xpert results and 9 with nondeterminate respiratory Xpert results were excluded.
One child with only swab method for stool 1, 3 children with nondeterminate stool Xpert results, 3 with no respiratory culture done, and 29 with contaminated or lost respiratory cultures were excluded.
One child with nondeterminate stool Xpert results and 9 with nondeterminate respiratory Xpert results were excluded.
One child with nondeterminate stool Xpert results, 3 with no respiratory culture done, and 29 with contaminated or lost respiratory cultures were excluded.