 |
 |
 |
 |
 |
 |
 |
|
|
|
|||||||||
|
|||||||||||
Infectious Diseases Clinical Pharmacist Department of Pharmacy Hospital del Mar Passeig Maritim 25-29 08003 Barcelona, Spain fax 34-3-248-32-56 sgrau{at}imas.imim.es
Clinical Pharmacist Department of Pharmacy Hospital del Mar
Clinical Pharmacist Department of Pharmacy Hospital del Mar
Published Online, November 14, 2006. www.theannals.com, DOI 10.1345/aph.1G728a
In our opinion, this pharmacoeconomic study has important limitations. First, the clinical trial on which it was based has been questioned.3 The superiority of linezolid over vancomycin could not be clearly proven. The study of the MRSA subgroup could not be statistically adequate, as an interaction test that was performed showed no significance. Second, the authors analyzed a subgroup of patients, all from the US, using unpublished data extracted from the general database of the baseline study. This makes it difficult for readers to reproduce or reanalyze the results. Despite the inclusion of a table showing characteristics of this subpopulation, some important data were missing, such as a severity score, race, and percentage of polimicrobial infections. Although this subgroup accounted for 60% of patients in the baseline study, it would be interesting to perform a heterogeneity analysis to confirm that this subgroup was not significantly different from the global population. Third, in the baseline study, the clinical cure rate in the MRSA subgroup was surprisingly missing, but this value was included in the pharmacoeconomic study. Thus, it is unknown whether this value was representative of the baseline study population.
Additionally, adverse effects were not considered in the pharmacoeconomic analysis. Some of these effects were clinically and economically important, and they should have been included in the study. Despite the fact that the total number of drug-related adverse events was not significantly different between groups, in the baseline study, when analyzed separately, thrombocytopenia, diarrhea, nausea, and rash were clearly different between groups. In the linezolid group, 13% of the patients experienced adverse effects; in the vancomycin group, only 5.6% of the patients were affected.
In conclusion, due to limitations of the methodology, the baseline trial for the pharmacoeconomic study did not show clear evidence of clinical superiority of linezolid over vancomycin. The subpopulation extracted from the clinical trial for use in the pharmacoeconomic investigation was not well characterized; this could well have affected the quality of the pharmacoeconomic study. In our opinion, a cost minimization study would be more appropriate when trying to determine which treatment alternative provides more benefits.
Footnotes
Comments on articles previously published are submitted to the authors of those articles. When no reply is published, either the author chose not to respond or did not do so in a timely fashion. Comments and replies are not peer reviewed.-ED.
References
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 |
 |
 |
 |
 |
 |
 |
