TABLE 2.

Performance of C.DIFF TOX A/B QUIK CHEK for stool specimens and isolates compared to toxigenic C. difficile culturea

Specimens (n)ResultToxigenic culture result% Sensitivity (95% CI)% Specificity (95% CI)% PPV (95% CI)% NPV (95% CI)
No. positiveNo. negative
GDH-positive stool specimens (172)Positive55252.9 (42.8-62.8)97.1 (89.8-99.6)96.5 (87.9-99.6)57.4 (47.8-66.6)
Negative4966
Culture isolates (137)Positive106193.8 (87.7-97.5)95.8 (78.9-99.9)99.1 (≥94.9)76.7 (57.7-90.1)
Negative723
  • a The toxigenicity of C. difficile isolates was determined by PCR for the presence of tcdA and tcdB genes of toxin A and B. Only specimens for which culture isolates were available were included in this analysis. NPV, negative predictive value; PPV, positive predictive value; 95% CI, 95% confidence interval.