Nosocomial methicillin-resistant and methicillin-susceptible, Staphylococcus aureus primary bacteremia: At what costs

OBJECTIVE: To determine the attributable hospital stay and costs for nosoco mial methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-res istant S aureus (MRSA) primary bloodstream infections (BSIs). DESIGN: Pairwise-matched (1:1) nested case-control study. SELLING: University-based tertiary-care medical center. PATIENTS: Patients admitted between December 1993 and March 1995 were eligi ble. Cases were defined as patients with a primary nosocomial S aureus BSI; controls were selected according to a priori matching criteria. MEASUREMENTS: Length of hospital stay and total and variable direct costs o f hospitalization. RESULTS: The median hospital stay attributable to primary nosocomial MSSA B SI was 4 days, compared with 12 days for MRSA (P=.023). Attributable median total cost for MSSA primary nosocomial BSIs was $9,661 versus $27,083 for MRSA nosocomial infections (P=.043). CONCLUSION: Nosocomial primary BSI due to S aureus significantly prolongs t he hospital stay. Primary nosocomial BSIs due to MRSA result in an approxim ate threefold increase in direct cost, compared with those due to MSSA (Inf ect Control Hosp Epidemiol 1999;20:408-411).