Testing Stewardship: A ‘Hard Stop’ to Reduce Inappropriate C. diff Testing

BACKGROUND: Patients may be over-diagnosed with C. difficile infection (CDI) due to colonization, especially if laxatives are used. We had implemented an alert to prompt providers to discontinue C. diff orders in the setting of laxative use. This initially decreased orders by about 25%, but became less effective over time. Our objective was to strengthen our C. diff testing stewardship by creating a “hard stop” to require providers to think critically about C. diff testing in the presence of laxative use or the absence of documented diarrhea. METHODS: Our two-hospital, >1100-bed community-based academic healthcare system performs all C. diff testing via PCR. We implemented our initial laxative alert, which notified providers but did not prohibit testing, in March 2015. In April 2017, we launched a new alert that fired >36 hours after admission, and assessed for documented diarrhea (>2 episodes/24 hours). If diarrhea was present, it would assess for any administered laxative within prior 24 hours. If neither criterion was met, the provider could only order C. diff testing by calling the laboratory and documenting the staff person’s name in the order; no further justification was required. We measured the number of C. diff tests completed per day, the number of calls made to lab, and CDI rates (using NHSN LabID definition). Balancing measures included monitoring oral vancomycin orders without C. diff testing, and delayed CDI diagnoses. RESULTS: At baseline, we observed a mean of 9 (SD, 4–14) C. diff orders daily. After initiating the hard stop alert, daily testing decreased by 30% (Fig. 1). Frequency of hospital-onset CDI dropped by 45% during first month of implementation (Fig. 2), from mean 3.6/week to 2/week. To date we have not detected delayed diagnoses or empiric treatment without testing; 18 override laboratory calls have been documented. CONCLUSION: Given PCR’s high sensitivity for C. diff, testing stewardship is critical to minimize false-positive cases of CDI, which lead to inappropriate treatment, prolonged length of stay, and hospital penalties. Requiring a phone call to order C. diff testing in the setting of laxative use or minimal diarrhea effectively reduced testing, and was well-accepted by nurses and providers. To date, no adverse effects have been detected. DISCLOSURES: All authors: No reported disclosures.