A Model to Evaluate the Impact of Hospital-Based Interventions Targeting False-positive Blood Cultures on Economic and Clinical Outcomes.

BACKGROUND: Blood culture contamination (BCC) increases length of stay (LOS) and leads to unnecessary anti-microbial therapy and/or hospital-acquired conditions (HACs).

AIM: We sought to quantify the magnitude of the additional LOS, costs to hospitals and society as well as the harm to patients attributable to BCC.

METHODS: A retrospective matched survival analysis was performed involving hospitalized patients with septicaemia-compatible symptoms. BCC costs, hospital-acquired conditions (HACs), and potential savings were calculated based on the primary LOS data, a modified Delphi process, and published sources. The cost analysis compared standard care to interventions for reducing BCC, and estimated annual economic and clinical consequences for a typical hospital and for the entire U.S.

FINDINGS: Patients with BCC experienced mean prolonged hospital stays of 2.35 days (p=0.0076). Avoiding BCCs would decrease costs by $6,463 ($4,818 from inpatient care, of which 53% was from reduced length of stay, and 26% was from reduced antibiotic use). Annually, in a typical 250- to 400-bed hospital, employing phlebotomists would save $1.3 million and prevent 24 HACs (including 2 C. difficile cases); based on clinical efficacy evidence, using the studied Initial Specimen Diversion Device (ISDD) would save $ 1.9 million and prevent 34 HACs (including 3 C. difficile cases). In the United States, the respective strategies would prevent 69,300 and 102,900 HACs (including 6,000 and 8,900 C. difficile cases) and costs of $5 and $7.5 billion.

CONCLUSION: Costs and clinical burdens associated with false-positive cultures are substantial and can be reduced by available interventions, including phlebotomists and ISDD use.