Blood culture quality assurance: findings from a RCPAQAP Key Incident Monitoring and Management Systems (KIMMS) audit of blood culture performance

Blood cultures (BC) are the gold standard investigation for bloodstream infection. Standards exist for BC quality assurance, but key quality indicators are seldom measured. The Royal College of Pathologists of Australasia Quality Assurance Programs (RCPAQAP) Key Incident Monitoring and Management Systems (KIMMS) invited laboratories for the first time to participate in an audit to determine adult BC positivity rates, contamination rates, sample fill volumes and the proportion received as a single set. The overall aim of the KIMMS audit was to provide laboratories with a mechanism for peer review and benchmarking. Results from 45 laboratories were analysed. The majority of laboratories (n=28, 62%) reported a positivity rate outside the recommended range of 8-15%. Contamination rates ranged from zero (n=5) to 12.5%, with seven laboratories (15%) reporting a contamination rate greater than the recommended 3%. Fifteen laboratories (33%) reported an average fill volume of less than the recommended 8-10 mL per bottle, with 11 laboratories (24%) reporting fill volumes of 5 mL or less whilst 13 (28%) laboratories were not able to provide any fill volume data. Thirteen laboratories (29%) reported that 50% or more of BC were received as single set, and eight (17%) were not able to report this data. This audit highlights there are deficiencies in BC quality measures across laboratories. To support BC quality improvement efforts, RCPAQAP KIMMS will offer a yearly BC quality assurance audit to encourage laboratories to monitor their BC quality performance.