The economic effect of oral linezolid versus intravenous vancomycin in the outpatient setting: the payer perspective

Oral antibiotic therapy can reduce complications and costs compared with intravenous (IV) therapy. The object of this study was to determine the health economic and resource utilization effects of outpatient treatment with oral linezolid relative to IV vancomycin. Longitudinal claims data from 80 health care plans were used. Patients 18 years and older, who did not have osteomyelitis, with a pharmacy claim for linezolid or vancomycin between January 1, 2002 and March 31, 2004 were eligible. Clinical and resource utilization data were collected for 12 months before and 35 days after treatment. Patients treated with linezolid were matched with controls treated with vancomycin, based on propensity scoring. Direct medical costs paid by health plans were compared. A total of 1,048 matched pairs were identified. Demographic and clinical characteristics were comparable between groups. Patients with linezolid claims had lower resource utilization versus those with vancomycin claims during follow-up, including fewer mean physician office visits (4.1+/-5.7 vs. 8.4+/-13.8 visits; P.001); lab/diagnostic claims (6.3+/-18.0 vs. 10.4 +/-15.2 claims; P.001); pharmacy claims (7.3+/-8.1 vs. 13.6+/-17.4 claims; P.001); emergency room visits (9.7% vs. 13.9%; P= .003) and hospitalization (15.3% vs. 19.1%; P= .024). Patients receiving vancomycin were more likely to be hospitalized or have an emergency room visit than patients receiving linezolid. Mean total adjusted cost was 4,707 dollars less for linezolid compared with vancomycin (8,401dollars vs. 13,108 dollars; P.001). Similar trends were observed for patients matched based on complicated skin and soft tissue infection diagnosis. Outpatient treatment with oral linezolid was associated with significantly lower resource utilization and total medical costs compared with IV vancomycin.