Test Performance Levels: The C Diff Quik Chek Complete® test has an overall sensitivity and specificity of 90.5% and 93.1%, respectively. The positive predictive value (PPV) and negative predictive value (NPV) for the test are 76.4% and 97.6%, respectively.
- Adequate fecal specimen collection and storage are important for the optimal performance of the test. Stool specimens properly collected and tested within 24 hours are recommended, otherwise, specimens can be stored between 2-80C for 72 hours or frozen and thawed.
- There may be some specimens that produce weak reactions causing the blue lines to appear faint or have a partial line. This can be the result of a number of factors such as the presence of low levels of antigen and/or toxin, the presence of binding substances, or inactivating enzymes in the feces.
- The test yields a qualitative result and the intensity of the blue color should not be interpreted quantitatively nor does it indicate the intensity of the presence of antigen or toxins.