Model to evaluate the impact of hospital-based interventions targeting false-positive blood cultures on economic and clinical outcomes

Abstract

Background: Blood culture contamination (BCC) increases length of stay (LOS) and leads to unnecessary antimicrobial therapy and/or hospital-acquired conditions (HACs). Aim: To quantify the magnitude of additional LOS, costs to hospitals and society, and harm to patients attributable to BCC. Methods: A retrospective matched survival analysis was performed involving hospitalized patients with septicaemia-compatible symptoms. BCC costs, 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 with interventions for reducing BCC, and estimated annual economic and clinical consequences for a typical hospital and for the USA as a whole. Findings: Patients with BCC experienced a mean increase in LOS of 2.35 days (P¼0.0076). Avoiding BCC would decrease costs by $6463 [$4818 from inpatient care (53% of which was from reduced LOS) and 26% from reduced antibiotic use]. Annually, in a typical 250-to 400bed hospital, employing phlebotomists would save $1.3 million and prevent 24 HACs (including two cases of Clostridium difficile infection); based on clinical efficacy evidence, use of the studied initial specimen diversion device (ISDD) would save $1.9 million and prevent 34 HACs (including three cases of C. difficile infection). In the USA, the respective strategies would prevent 69,300 and 102,900 HACs (including 6000 and 8900 cases of C. difficile infection) and save $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 use of ISDD.

Modern Blood Culture

“… 10 As noted, the use of commercial diversion devices reduced contamination rates, 11 which in models is projected to lead to considerable cost savings and reductions in patient length of stay. 13 , 14 In 2 recent studies, blood culture contamination was reduced without using expensive commercial diversion devices, by diverting a small amount of blood using vacutainer tubes by changing the test draw order, which could also be accomplished for blood cultures alone by simply discarding the diverted portion. 15 , 16 …”

Evaluation of an Initial Specimen Diversion Device (ISDD) on Rates of Blood Culture Contamination in the Emergency Department

“…However, blood cultures commonly become contaminated with environmental or skin-residing organisms. 1,2 Contaminated cultures can lead to misdiagnosis, increased length of stay (LOS) and hospital costs, and unnecessary testing and antibiotic use. [1][2][3] National contamination rate recommendations are set at less than 3% by the Clinical and Laboratory Standards Institute (CLSI).…”

“…1,2 Contaminated cultures can lead to misdiagnosis, increased length of stay (LOS) and hospital costs, and unnecessary testing and antibiotic use. [1][2][3] National contamination rate recommendations are set at less than 3% by the Clinical and Laboratory Standards Institute (CLSI). 4 However, institutions across the U.S. have varying and often higher contamination rates ranging from 2 -10%.…”

“…There are many organisms that can lead to contaminated blood cultures, but among the most common are coagulase-negative staphylococci, Corynebacterium species, Bacillus species other than Bacillus anthracis, Propionibacterium acnes, Micrococcus species, viridans group streptococci, and Clostridium perfringens. 1,2,3,5 All of these pathogens can represent true bacteremia when found in a blood culture. Obtaining accurate blood cultures will prevent potential errors in diagnosing, unwarranted lab tests, antibiotic usage, and lower total costs hospital wide.…”

“…Blood culture contaminants increase total hospital costs from $4,500 -13,000 per contaminant. 2,4,6,7 For the current study, the median of the existing data of $8,750 per contaminant was used. Of note, several of the existing financial outcome studies were older, with one of them being from over a decade ago.…”