Cost and healthcare utilization of methicillin-resistant Staphylococcus aureus bacteremia estimated from linked antimicrobial resistance surveillance and hospital claims data in Japan

OBJECTIVE: To compare the incremental costs and healthcare utilization of methicillin-resistant Staphylococcus aureus (MRSA) bacteremia with those of methicillin-susceptible S. aureus (MSSA) bacteremia. DESIGN: Retrospective cohort study using data from April 2014 to March 2015. SETTING: Antimicrobial resistance surveillance and hospital claims data from 16 Japanese hospitals. PATIENTS: The study included 73 patients with S. aureus bacteremia: 23 with MRSA and 50 with MSSA. METHODS: MRSA bacteremia was identified using blood cultures and drug-susceptibility tests. MRSA- and MSSA-related medical practices were evaluated. The costs were calculated and compared. All the medical costs were classified into empirical and definitive therapy periods and expressed in Japanese yen (JPY, 1 USD = 106 JPY). Additionally, costs at aggressive and passive bacterial test-performing facilities were compared. RESULTS: No significant differences existed in MRSA-related resource use per patient episode between MRSA and MSSA bacteremia during empirical therapy. However, during definitive therapy, in MRSA bacteremia compared with MSSA bacteremia, this difference was higher. The average MRSA-related costs of empirical therapy for MRSA and MSSA were 13,380 and 9,140 JPY (126 and 86 USD) per patient, and for definitive therapy, they were 69,810 and 29,510 JPY (659 and 278 USD) per patient, respectively. No significant differences were noted. Conversely, the average examination costs during definitive therapy differed significantly: 9,740 vs 3,850 JPY (92 vs 36 USD), respectively (P = .0294). Furthermore, the incremental costs in aggressive facilities were lower for the definitive therapy period than those in passive facilities. CONCLUSIONS: In the definitive therapy period, MRSA bacteremia had higher incremental costs and greater use of healthcare resources. In addition, the incremental costs in aggressive facilities were lower than those in passive facilities.