2015. Minimal Impact of Blood Culture Contaminants on Patient Care Decisions May Limit Cost-Effectiveness of Interventions to Reduce Contamination Rates

BACKGROUND: High blood culture (BC) contamination rates have been associated with increased healthcare cost, antimicrobial use, and extended length of stay. Interventions using blood culture diversion devices (BCDD) reduce contamination rates, but often increase equipment costs compared with traditional collection techniques. Cost savings will only be achieved, therefore, if contaminated BCs do in fact lead to expensive care decision. The purpose of this study was to define the actual impact of contaminated BCs on patient care as a means of determining the cost-effectiveness of implementing BCDD at our institution. METHODS: A retrospective review of all contaminated BCs collected in our Emergency Department (ED) from July 2018 to December 2018 was completed. Data including antimicrobial therapy, admission status, laboratory orders, and co-morbidities for patients with contaminated cultures, as defined by the College of American Pathologist (CAP), were recorded. Laboratory costs included rapid molecular assays performed for patients admitted from the ED, as well as technologist effort and media costs for BC work-up. RESULTS: During this study period, out of a total of 4,176 blood draws, there were 118 BCs (2.8%) that met the CAP definition of contamination. Of all contaminated cultures, only 12.7% (n = 15) of patients were treated because of a positive BC, while 68.6% were given antibiotics due to other comorbidities; A total of 22 patients (18.6%) did not receive any antibiotics during the encounter. The most common therapy for treated contaminants was vancomycin (14/15, 93.34%) for an average of 5.2 days. No patients with contaminated BCs were admitted to the hospital because of a positive result; 92.3% of patients with contaminated BCs were admitted, however, for a different diagnosis. Based on average treatment and laboratory costs, the total costs per contaminant were estimated at $170 USD. CONCLUSION: Contamination of BCs collected in the ED does not routinely lead to antimicrobial therapy or hospital admissions at our institution. This minimal impact of BC contaminants on patient care decisions and healthcare costs limits the cost-effectiveness of interventions such as BCDD at our institution. These findings may be specific to our institution based on our clinical practice and unique patient population. DISCLOSURES: All authors: No reported disclosures.