From Implementation to Sustainability: A Dual-Campus Analysis of Blood Culture Contamination Reduction Using Collection and Diversion Best Practices

Blood culture contamination is a significant clinical issue which contributes to diagnostic error, unnecessary antibiotic use, and increased health care costs. Emergency departments have disproportionately higher contamination rates, highlighting the need for effective, sustainable best practices to reduce blood culture contamination.

This quality improvement project was conducted across 2 emergency departments within an acute care health care system in the United States. The study population included all adult patients aged 18 years or older who underwent nurse-collected blood cultures. A multifaceted intervention was implemented using standardized collection procedures, staff education, performance feedback, and a passive blood culture diversion device. After a 4-month run-in period, blood culture contamination rates during the 12-month pre-intervention period were compared with those across the 24-month post-intervention sustainability period to evaluate the durability of the intervention's effect.

Combined mean baseline blood culture contamination rates for the 2 emergency departments (4.28%) exceeded recommended benchmarks. During the post-intervention sustainability period, combined mean blood culture contamination rates decreased to 1.59%, representing a 62.8% reduction. This decrease was statistically significant (Welch's t test, P < .001) and associated with a very large effect size (Cohen's d = 2.34), indicating a substantial and clinically meaningful improvement.

Implementation of a standardized blood culture collection protocol incorporating a blood culture diversion device resulted in a significant and sustained reduction in blood culture contamination rates. These findings support bundled, evidence-based approaches to achieve contamination rates approaching ≤1%, with important implications for diagnostic stewardship and patient safety.