Reduction of Blood Culture Contamination Through an Evidence-Based, Multidisciplinary Quality Improvement Initiative

Contaminated blood cultures can lead to diagnostic errors, inappropriate antimicrobial use, and prolonged hospital stays. Although a contamination rate ≤3% is generally considered as an acceptable upper limit, the rate in our hospital exceeded this benchmark.

We aimed to reduce blood culture contamination rates by a hospital-wide, evidence-based quality improvement (QI) approach.

A multidisciplinary team including clinical pathology, infectious diseases, nursing, and quality management implemented a QI initiative using Plan-Do-Study-Act (PDSA) cycles. Root cause analysis identified inconsistent disinfection practices, inadequate formal training, and lack of feedback. Interventions included standard operating procedures revision based on current best practices, development of standardized instruction and e-learning, monthly unit-level feedback, and device standardization.

The preintervention contamination rate was 4.74% (range: 4.08%-5.77%). After implementation, the rate decreased to 2.82% (2.71%-2.90%). Improvement was sustained over 1 year, with a rate of 2.42% (2.17%-2.65%). Additional outcomes included increased blood culture volume and reduced reporting time.

A multidisciplinary collaboration and evidence-based QI initiative targeting all staff involved in blood culture collection was the key to effectively reducing and sustaining lower contamination rates.

Blood culture contamination is a modifiable quality metric. Evidence-based, multidisciplinary QI programs using PDSA cycles are a replicable framework for improving patient safety, diagnostic accuracy, and antimicrobial stewardship.