Comparison of C. difficile kits (333 samples; PPV&NPV=positive & negative predictive values)
| TechLab TOX A/B II | Meridian Premier Toxins A 8, B | Remel Xpect C. difficile toxin A/B | Meridian ImmunoCard Toxins A & B | TechLab ToxA/B QuikChek | Cytotoxin assay | |
|---|---|---|---|---|---|---|
| (a) Gold standard = cytotoxin assay: | ||||||
| sensitivity (%) | 97.1 | 96.6 | 68.1 | 87.0 | 81.2 | |
| specificity (%) | 92.0 | 95.5 | 99.2 | 97.0 | 9S.5 | |
| PPV (%) | 76.1 | 65.0 | 95.9 | 90.9 | 90.0 | |
| WPV (%) | 99.2 | 99.6 | 92.3 | 96.6 | 95.2 | |
| (b) Consensus – any sample with at least 2 tests positive considered a true positive: | ||||||
| sens itlvlty (%) | 96.7 | 98.7 | 65.3 | 86.7 | 80.0 | 90.7 |
| specificity (%) | 94.6 | 97.7 | 100 | 99.6 | 100 | 99.6 |
| PPV (%) | 84.1 | 92.5 | 100 | 9G.5 | 100 | 9S.6 |
| NPV (%) | 99.6 | 99.6 | 90.8 | 96.3 | 94.5 | 97.3 |