Assay | No. of samples with the following assay result: | Cytotoxigenic culture result | No. of samples tested | Sensitivity (%) (95% CI)^{a} | Specificity (%) (95% CI)^{a} | |||
---|---|---|---|---|---|---|---|---|

Positive | Negative | Equivocal | Invalid | |||||

Cytotoxin test | 108 | 17 | 0 | 0 | Positive | 125 | 86.4 (79.1-91.9) | 99.2 (97.9-99.8) |

4 | 471 | 0 | 0 | Negative | 475 | |||

Premier toxin A+B | 101 | 24 | 0 | 0 | Positive | 125 | 80.8 (72.3-87.3) | 97.5(95.5-98.6) |

12 | 463 | 0 | 0 | Negative | 475 | |||

GA Clostridium difficile antigen | 86 | 39 | 0 | 0 | Positive | 125 | 68.8 (59.9-76.8) | 91.4 (88.4-93.7) |

41 | 454 | 0 | 0 | Negative | 475 | |||

Ridascreen toxin A/B | 75 | 50 | 0 | 0 | Positive | 125 | 60.0 (50.9-68.7) | 95.6 (93.2-97.2) |

20 | 434 | 1 | 0 | Negative | 475 | |||

Techlab toxin A/B II | 100 | 25 | 0 | 0 | Positive | 125 | 80.0 (71.9-86.6) | 96.0 (93.7-97.5) |

19 | 456 | 0 | 0 | Negative | 475 | |||

Remel ProSpecT | 102 | 23 | 0 | 0 | Positive | 125 | 81.6 (73.7-87.9) | 93.3 (90.6-95.4) |

32 | 443 | 0 | 0 | Negative | 475 | |||

Vidas C. difficile Tox A/B | 100 | 16 | 9 | 0 | Positive | 125 | 80.0 (71.9-86.6) | 97.3 (95.2-98.5) |

2 | 462 | 11 | 0 | Negative | 475 | |||

Remel Xpect | 86 | 31 | 8 | 0 | Positive | 125 | 68.8 (59.9-76.8) | 99.4 (98.2-99.9) |

3 | 472 | 0 | 0 | Negative | 475 | |||

Techlab Tox A/B Quik Chek | 93 | 32 | 0 | 0 | Positive | 125 | 74.4 (65.8-81.78) | 98.9 (97.6-99.7) |

3 | 470 | 1 | 1 | Negative | 475 | |||

Premier Immunocard A + B | 86 | 29 | 0 | 10 | Positive | 125 | 68.8 (59.9-76.8) | 93.0 (90.4-95.2) |

2 | 442 | 0 | 31 | Negative | 475 | |||

Techlab C. diff Chek-60 | 92 | 13 | 0 | 0 | Positive | 105 | 87.6 (72.4-93.0) | 94.3 (91.7-96.2) |

26 | 433 | 0 | 0 | Negative | 459 | |||

BD GeneOhm C. difficile | 92 | 11 | 0 | 1 | Positive | 104 | 88.5 (80.3-93.6) | 95.4 (92.9-97.0) |

16 | 433 | 0 | 5 | Negative | 454 |

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*a*The sensitivity and specificity of the assays compared to the gold standard cytotoxigenic culture results are shown. The sensitivity and specificity are given as percentages, and the 95% confidence interval (95% CI) values are shown in parentheses.