2342. Elimination of Reflexive C. difficile PCR Testing Among Inpatients Resulted in Cost Savings Without Adverse Events

Abstract

BackgroundDiagnosis of C. difficile infection is imperfect and various algorithms have been proposed. While PCR is sensitive for detecting toxin-carrying C. difficile, it leads to overdiagnoses resulting in antibiotic overuse and potentially unnecessary healthcare costs.MethodsWe performed a study of C. difficile cases after changing the testing protocol from reflexive vs. physician-requested PCR in cases of indeterminant EIA testing (antigen +, toxin −). The study was conducted among inpatient adults at four large hospitals in the southern California area and evaluated two 6-month periods: pre-intervention: (September 5, 2016–March 5, 2017) and post-intervention (3/6/2017–9/6/2017). Only the first C. difficile test during a period per patient was evaluated. Primary outcome was change in number of C. difficile diagnoses. Secondary outcomes included adverse events (missed cases of C. difficile and 30-day readmissions) and cost savings (accounting for PCR, isolation, and treatment costs).ResultsA total of 500 EIA indeterminant C. difficile test results were evaluated, 281 pre- and 219 post-intervention. There were no statistically significant differences in demographics, laboratory values (WBC, Cr), or hospital site between the study periods. A PCR was performed in 99.6% (280/281; one not performed due to an inhibitor) and 66% (144/219) in the pre- vs. post-intervention periods (P < 0.01); the PCR was positive in 65% (n = 182 and n = 94, respectively) in both periods. The change in testing strategy resulted in a 49% reduction in PCR testing and 48% fewer C. difficile cases. There were no differences between study periods in 30-day readmissions for all-cause (P = 0.96), GI-related illness (P = 0.93) or C. difficile (P = 0.47), nor in new or recurrent C. difficile cases (P > 0.99). No patient without a PCR and not treated was later diagnosed with C. difficile infection. Each reflexive PCR avoided led to a cost savings of $4,384/patient.ConclusionDiagnostic stewardship is an emerging area that can potentially reduce overdiagnosis and overtreatment of a variety of infectious diseases. Our study showed that changing C. difficile PCR testing among EIA-indeterminant cases from reflexive to requiring a physician order resulted in valuable cost savings without associated adverse events.Disclosures All authors: No reported disclosures.