Cost analysis of switching from i.v. vancomycin to p.o. linezolid for the management of methicillin-resistant Staphylococcus species.
BACKGROUND
Infections with methicillin-resistant Staphylococcus species (MRSS) are associated with higher treatment costs than infections with methicillin-sensitive Staphylococcus species in the United States--partly because of an increased length of hospital stay (LOS).


OBJECTIVE
This study used pharmacoeconomic modeling to evaluate the costs and outcomes associated with the use of i.v. vancomycin compared with p.o. linezolid in the treatment of MRSS-infected patients.


METHODS
A retrospective chart review was used to determine the number of cases with confirmed or presumed MRSS infections treated with i.v. vancomycin during calendar-year 2000 at the Veterans Affairs Greater Los Angeles Healthcare System inpatient facility. Patients who were eligible for a switch to p.o. linezolid with or without early discharge to home were identified. Cost differences associated with conversion from i.v. to p.o. therapy (compared with continued i.v. therapy) were estimated based on a mean decreased LOS and a decrease in the costs associated with catheter-related adverse events. Rates and costs of catheter-related adverse events were based on estimates from the literature. Sensitivity analyses were performed by variation of the estimated mean LOS decrease in the SD and by variation of the estimates for incidence and costs related to catheter complications. Costs were measured in year 2000 US dollars, and differences were not assessed for statistical significance.


RESULTS
Of 177 patients treated with i.v. vancomycin, 103 (58%) were eligible for conversion to p.o. linezolid and 55 (31%) were eligible for early discharge from the hospital with continuation of p.o. therapy. Early discharge was associated with a mean (SD) LOS decrease of 3.3 (2.9) days. Annual mean total cost savings in patients eligible for conversion from i.v. vancomycin to p.o. linezolid with early discharge were $294,750 (range, $35,730-$553,790). For cases eligible for inpatient conversion from i.v. vancomycin to p.o. linezolid therapy (n=48), the mean total annual cost difference was an increase of $6340 for p.o. linezolid (range, -$12,910 to $11,900).


CONCLUSIONS
These results--although partly based on estimates from the literature, rather than direct measurements--support the use of p.o. linezolid with or without early discharge as a potential cost-savings alternative for eligible patients treated with a full course of i.v. vancomycin for suspected or confirmed MRSS infection.
McCollum
Marianne
M
Department of Clinical Pharmacy, University of Colorado Health Sciences Center School of Pharmacy, Denver, Colorado 80262, USA. marianne.mccollum@uchsc.edu
Rhew
David C
DC
Parodi
Stephen
S
D000081:Acetamides / Q000191:economics* / Q000627:therapeutic use; D000284:Administration, Oral; D000900:Anti-Bacterial Agents / Q000191:economics* / Q000627:therapeutic use; D000890:Anti-Infective Agents / Q000191:economics* / Q000627:therapeutic use; D003365:Costs and Cost Analysis; D005260:Female; D006787:Hospitals, Veterans; D006801:Humans; D007275:Injections, Intravenous; D000069349:Linezolid; D015141:Los Angeles; D008297:Male; D016106:Methicillin Resistance; D023303:Oxazolidinones / Q000191:economics* / Q000627:therapeutic use; D013203:Staphylococcal Infections / Q000188:drug therapy*; D014640:Vancomycin / Q000191:economics* / Q000627:therapeutic use
D000081:Acetamides; D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D023303:Oxazolidinones; D014640:Vancomycin; D000069349:Linezolid