Solitary blood cultures: a College of American Pathologists Q-probes study of 132,778 blood culture sets in 333 small hospitals

Abstract

Objective: To determine the frequency with which solitary blood culture samples were submitted to laboratories serving small hospitals and to ascertain whether certain hospital practices relating to the performance of blood cultures were associated with lower solitary blood culture rates (SBCRs).

Design: Participants in the College of American Pathologists Q-Probes laboratory quality improvement program collected data prospectively on the numbers of solitary blood culture sets from adult patients submitted to their laboratories and answered questions about their institutions' practice characteristics relating to the collection of blood culture specimens.

Setting and participants: Three hundred thirty-three public and private institutions with a median occupied bed size of 57. Participants were located in the United States (n = 329), Canada (n = 3), and Australia (n = 1).

Main outcome measure: The solitary blood culture rate was defined as the number of instances in which only 1 blood culture venipuncture was performed on an individual patient during a 24-hour period divided by the total number of blood culture venipunctures that were performed during the study period.

Results: Participants submitted data on 132 778 adult patient blood culture sets. The SBCRs were 3.4% or less in the top-performing 10% of participating institutions (90th percentile and above), 12.7% in the midrange of participating institutions (50th percentile), and 42.5% or more in the bottom-performing 10% of participating institutions (10th percentile and below). In half the participating institutions, the SBCRs for inpatients were 8.3% or less and for outpatients, 22% or less. Solitary blood culture rates were lower for institutions in which phlebotomists rather than nonphlebotomists routinely collected blood culture specimens, in which internal policies required drawing at least 2 blood culture sets, in which hospital personnel contacted clinicians when their laboratories received requests for solitary blood culture sets, and in which quality control programs monitored SBCRs routinely.

Conclusions: Hospitals can achieve SBCRs under 5%. Those hospitals with particularly high SBCRs may lower their rates by altering certain institutional practices.