Abstract

Objective: To determine the financial impact of Coagulase-Negative Staphylococcus (CoNS)- positive blood cultures.

Design: Retrospective chart review.

Setting: Tertiary care cancer hospital.

Patients: All episodes of CoNS bacteremia during the first 6 months of 2001 were identified. Episodes from the intensive care unit, those never treated, and those treated with antibiotics before the culture was drawn or became positive were excluded. Chart review was performed in a random sample of patients to estimate the cost of each component of medical care attributable to the management of CoNS. Each patient-episode was retrospectively designated as infection or contaminant by an expert reviewer.

Results: In the 6 month study period, 137 episodes of CoNS were treated. Medical records for 43 (39%) of 111 eligible patients were extracted. The average cost of managing the 43 CoNS episodes was $7,594. For the subset of 16 patients with increased length of stay (LOS) attributable to CoNS, the mean cost was $15,919, 77% due to hospital day charges. The 43 episodes were retrospectively designated either infection (n=31) or contaminant (n=12); attributable cost differed by assigned category. The mean cost for 31 patients with infection was $8,858. Six episodes, designated as contaminants by both primary team and expert review, had a mean cost of $1,881. Six additional episodes, treated as infection by the primary team but reassigned as contaminant on retrospective review, had a mean cost of $7,127. Applying the proportion of patients (6/43 or 14%) reclassified as contaminant to the annual number of treated blood cultures (2×137) would project to an annual savings of $201,237 ($7,127 minus $1,881 or $5,246/episode) at our hospital.

Conclusion: In the management of CoNS bacteremia, unneeded treatment of contaminants as true infection costs up to $200,000 a year at our hospital. Infectious disease or antibiotic management program management may result in a reduction of this cost.

Keywords: Bloodstream infection; Coagulase-negative staphylococcus; Cost and cost analysis