Development and validation of a standardized blood culture contamination definition and metric dashboard for a large health care system

Laboratory approaches to determining blood culture contamination rates: an ASM Laboratory Practices Subcommittee report

Blood culture contamination (BCC) is the presence of specific commensal and environmental organisms cultivated from a single blood culture set out of a blood culture series and that do not represent true bacteremia. BCC can impact quality of care and lead to negative outcomes, unnecessary antibiotic exposure, prolonged hospital stays, and substantial costs. As part of the laboratory's quality management plan, microbiology laboratory personnel are tasked with monitoring BCC rates, preparing BCC rate reports, and providing feedback to the appropriate committees within their healthcare system. The BCC rate is calculated by the laboratory using pre-set criteria. However, pre-set criteria are not universally defined and depend on the individual institution's patient population and practices. This mini-review provides practical recommendations on elaborating BCC rate reports, the parameters to define for the pre-set criteria, how to collect and interpret the data, and additional analysis to include in a BCC report.

Diagnostic Stewardship: A Systematic Review and Meta-analysis of Blood Collection Diversion Devices Used to Reduce Blood Culture Contamination and Improve the Accuracy of Diagnosis in Clinical Settings

Background

Blood culture contamination may lead to misdiagnosis, overutilization of antibiotics, and prolonged length of stay. Blood specimen diversion devices can reduce contamination rates during blood culture collection procedures. We performed a systematic literature review and meta-analysis evaluating the influence of blood specimen diversion devices in blood culture contamination rates.

Methods

We searched Medline, Cumulative Index to Nursing and Allied Health Literature, Embase, Cochrane, Scopus, and Web of Science, from database inception to 1 March 2023, for studies evaluating the impact of a diversion device on blood culture contamination. Blood culture contamination was a positive blood culture with microorganisms not representative of true bacteremia, but rather introduced during collection or processing the blood sample. Random-effects models were used to obtain pooled mean differences, and heterogeneity was assessed using the I2 test.

Results

Of 1768 screened studies, 12 met inclusion criteria for this systematic literature review. Of them, 9 studies were included in the meta-analysis. Studies were substantially heterogeneous, but stratified analyses considering only high-quality studies revealed that venipuncture using a diversion device was associated with a significant reduction in blood culture contamination in comparison to the standard procedure of collection (pooled odds ratio [OR], 0.26 [95% confidence interval {CI}, .13-.54]; I2 = 19%). Furthermore, the stratified analysis showed that the adoption of a diversion device did not reduce the detection of true infection (pooled OR, 0.85 [95% CI, .65-1.11]; I2 = 0%).

Conclusions

Blood culture diversion devices was associated with decreased contamination rates and could improve quality of care, reduce costs, and avoid unnecessary antibiotic use.