Regardless of the method or sequence of testing, when testing the same unformed stool specimen, the result of the last test performed is used to determine if the CDI Laboratory Assay definition is met and a LabID event is submitted to NHSN.   Examples of different algorithms and interpretations for event reporting are provided in the MDRO protocol:  MDRO protocol [PDF – 2 MB]. Only when the final report has specific test times attached to each of the individual testing methods (for example, antigen/toxin and PCR) can one make a valid determination of which test is performed first and which is performed last. If there are no specific test times/time stamps attached to each individual testing method on the final lab report, consider the tests as performed simultaneously and any positive is eligible for use.