Clostridium difficile Laboratory Identification Event Reporting – A Need for Diagnostic Stewardship

BACKGROUND: Clostridium difficile LabID event reporting uses electronic laboratory results without chart review. Nucleic acid amplification testing is common in the US. A positive result may represent colonization or C. diff infection (CDI). We review C.difflabID events to ascertain if Hospital-Onest CDI (HO CDI). For non-HO CDI, we identify reason and use a matrix to prioritize clinical areas for intervention efforts. METHODS: Each C. difflab ID event from Jan 2015 to June 2016 at academic center had chart review for HO CDI; defined significant diarrhea, not present on admission, with no laxatives in prior 48 hours. For non HO-CDI events, reason and receipt of antibiotic treatment within 14 days of the positive test were retrospectively noted. A prioritization matrix, where clinical services were ranked according to number of lab ID events (service’s contribution to the facility C. diffLabID), was multiplied by a rank based on percent of inappropriate tests giving an overall prioritization score for where intervention resources could potentially best be used. RESULTS: There were 490 C difficile LabID events; 284 (58%) were HO-CDI; 206 (42%) were inappropriate or delayed testing. Of the 190 with available medical records at time of retrospective review, reasons for not meeting the HO-CDI included laxative use within the previous 48 hours (41%), no clinically significant diarrhea (49.5%); delayed testing (9.5%). See figure. Of 172 patients with inappropriate testing, 159 (92%) were treated for CDI. Medicine and psychiatry ranked first and second on prioritization matrix. See table. CONCLUSION: Nearly half of C. diff LabID events were not true HO CDI, but inappropriate or delayed tests. Prioritization matrix identified medicine and psychiatry as areas where diagnostic stewardship interventions could affect most on facility C. diff LabID. DISCLOSURES: K. C. Carroll, GenePOC, Inc.: Grant Investigator, Grant recipient