OBJECTIVES: This study aimed to compare total medical cost (TMC) among inpatients with methicillin resistant Staphylococcus aureus (MRSA) and methicillin sensitive S. aureus (MSSA) infections, and to identify risk factors associated with TMC, especially methicillin resistance.

METHODS: A multicenter, retrospective, observational comparative study was conducted among inpatients with MRSA and MSSA infections. Data were collected from three hospitals in China during 2013 and 2015. We classified the S. aureus cases as MRSA or MSSA based on antibiotic susceptibility testing. Univariate and multivariate analyses were used to identify factors associated with TMC

RESULTS: A total of 367 inpatients were admitted with S. aureus, 210 of whom had MRSA. Compared with MSSA cases, MRSA cases were associated with a higher mean medical cost in univariate analysis (TMC: 38442 vs 12585, p<0.000; medication cost: 18306 vs 5820, p<0.000; antibiotic cost: 4562 vs 1172, p<0.000; diagnostic cost: 4445 vs 1854, p<0.000; treatment cost: 6643 vs 2091, p<0.000; material cost: 3835 vs 686, p<0.000, other cost: 395 vs 18, p=0.001). After multivariate adjustment, methicillin resistance (b=0.253), admission unit (medical unit: reference; surgical unit: b=0.0143; ICU unit: b=0.085; other unit: b=0.040), number of diagnosis (b=0.018), number of surgery (b=0.062), neoplasms (b=0.160), endocrine/nutritional/metabolic diseases (b=0.178), cerebrospinal/joint fluid (Blood: reference; cerebrospinal/joint fluid: b=-0.056), intensive care unit stay (b=0.004), length of stay before first culturing (b=0.005) were significantly associated with TMC.

CONCLUSIONS: Our study highlights the heavy financial burden imposed by S. aureus and methicillin resistance on the Chinese healthcare system.