Reduction in blood culture contamination rate by feedback to phlebotomists.

Abstract

To determine whether monitoring and feedback of blood culture contamination rates to phlebotomists would reduce the overall contamination rate. Before and after interventional study. Blood cultures collected by venipuncture by phlebotomists at Foothills Hospital, Calgary, a tertiary care teaching hospital. Feedback of contamination rates calculated from a laboratory definition of blood culture contamination. The definition was based on isolation of typical skin organisms from a single blood sample when two samples were obtained. Reduction in the laboratory-defined contamination rate in the second year. Of 8462 cultures collected by phlebotomists in the prefeedback year, 224 (2.6%) were contaminated, compared to 131 (1.4%) of 9282 cultures in the postfeedback year. There was a rise in the total number of positive cultures regarded as significant but a fall in the number of coagulase-negative staphylococci that were regarded as significant by our definition. The rate of contamination in blood cultures collected by nonphlebotomists did not change. The contamination rate decreased after feedback. Our definition of contamination was imperfect and could be improved, but it was valuable in achieving a real reduction in blood culture contamination.