Cost-effectiveness analysis of linezolid compared with vancomycin for the treatment of nosocomial pneumonia caused by methicillin-resistant Staphylococcus aureus.
OBJECTIVE
This study compared the cost-effectiveness of linezolid and vancomycin in the treatment of patients with nosocomial pneumonia (NP) caused by methicillin-resistant Staphylococcus aureus (MRSA).


METHODS
A retrospective decision-analytic model was applied to pooled data from 2 prospective, randomized, controlled, double-blind studies, and claims data from a large health plan (3.3 million members) located in the Mid-Atlantic region. Using hospital claims for patients in the health plan with suspected NP, we then determined their daily billed (submitted) hospital charges for 4 mutually exclusive potential health outcomes of linezolid or vancomycin treatment: survival with bacteremia, survival without bacteremia, nonsurvival with bacteremia, and nonsurvival without bacteremia. To generate the expected total daily billed hospital charge for each drug-treatment group, we weighted the determined daily billed hospital charges by the probabilities of each outcome developing in each treatment arm, as derived from the clinical-trial data. Drug acquisition costs were then incorporated, and the difference in expected total costs relative to the difference in rates of survival between the linezolid and vancomycin arms was used to calculate the incremental cost-effectiveness ratio (ICER) for linezolid.


RESULTS
Costs were higher for nonsurviving patients compared with surviving patients. Estimated median daily billed treatment charges were $2888 for linezolid and $2993 for vancomycin. Based on Monte Carlo simulations, the respective 95% CIs were $2671 to $3106 and $2615 to $3372. Using mean treatment durations of 11.3 and 10.7 days, respectively, we obtained expected total hospitalization charges of $32,636 for linezolid treatment (95% CI, $30,182-$35,098), compared with $32,024 for vancomycin treatment (95% CI, $27,978-$36,078). The ICER for linezolid per life saved was $3600.


CONCLUSIONS
The higher acquisition cost of linezolid was almost completely offset by improved survival and a reduction in health care costs associated with improved survival. As a result, linezolid was almost cost-neutral compared with vancomycin in the treatment of NP caused by MRSA.
Daniel Mullins
C
C
University of Maryland School of Pharmacy, Baltimore, Maryland, USA. Electronic address: dmullins@rx.umaryland.edu.
Kuznik
Andreas
A
University of Maryland School of Pharmacy, Baltimore, Maryland, USA.
Shaya
Fadia T
FT
University of Maryland School of Pharmacy, Baltimore, Maryland, USA.
Obeidat
Nour A
NA
University of Maryland School of Pharmacy, Baltimore, Maryland, USA.
Levine
Andrew R
AR
University of Maryland School of Pharmacy, Baltimore, Maryland, USA.
Liu
Larry Z
LZ
US Outcomes Research, Pfizer Inc., New York, New York, USA.
Wong
Winston
W
Pharmacy Management, CareFirst BlueCross BlueShield of Maryland Inc., Baltimore, Maryland, USA.
D000081:Acetamides / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D003362:Cost-Benefit Analysis; D003428:Cross Infection / Q000188:drug therapy*; D005260:Female; D017048:Health Care Costs; D006801:Humans; D000069349:Linezolid; D008297:Male; D016106:Methicillin Resistance; D008875:Middle Aged; D023303:Oxazolidinones / Q000627:therapeutic use*; D011023:Pneumonia, Staphylococcal / Q000188:drug therapy*; D016032:Randomized Controlled Trials as Topic; D013211:Staphylococcus aureus / Q000187:drug effects*; D014640:Vancomycin / Q000627:therapeutic use*
D000081:Acetamides; D000900:Anti-Bacterial Agents; D023303:Oxazolidinones; D014640:Vancomycin; D000069349:Linezolid