title: A propensity score analysis shows that empirical treatment with linezolid does not increase the thirty-day mortality rate in patients with Gram-negative bacteremia.
abstract: The role of linezolid in empirical therapy of suspected bacteremia remains unclear. The aim of this study was to evaluate the influence of empirical use of linezolid or glycopeptides in addition to other antibiotics on the 30-day mortality rates in patients with Gram-negative bacteremia. For this purpose, 1,126 patients with Gram-negative bacteremia in the Hospital Clinic of Barcelona from 2000 to 2012 were included in this study. In order to compare the mortality rates between patients who received linezolid or glycopeptides, the propensity scores on baseline variables were used to balance the treatment groups, and both propensity score matching and propensity-adjusted logistic regression were used to compare the 30-day mortality rates between the groups. The overall 30-day mortality rate was 16.0% during the study period. Sixty-eight patients received empirical treatment with linezolid, and 1,058 received glycopeptides. The propensity score matching included 64 patients in each treatment group. After matching, the mortality rates were 14.1% (9/64) in patients who received glycopeptides and 21.9% (14/64) in those who received linezolid, and a nonsignificant association between empirical linezolid treatment and mortality rate (odds ratio [OR], 1.63; 95% confidence interval [CI], 0.69 to 3.82; P = 0.275, McNemar's test) was found. This association remained nonsignificant when variables that remained unbalanced after matching were included in a conditional logistic regression model. Further, the stratified propensity score analysis did not show any significant relationship between empirical linezolid treatment and the mortality rate after adjustment by propensity score quintiles or other variables potentially associated with mortality. In conclusion, the propensity score analysis showed that empirical treatment with linezolid compared with that with glycopeptides was not associated with 30-day mortality rates in patients with Gram-negative bacteremia.
authors.affiliation: Department of Internal Medicine, University Hospital of Salamanca and Institute of Biomedical Research of Salamanca (IBSAL), Salamanca, Spain.
authors.forename: Hugo-Guillermo
authors.initials: HG
authors.lastname: Ternavasio-de la Vega
authors.affiliation: Department of Internal Medicine, University Hospital of Salamanca and Institute of Biomedical Research of Salamanca (IBSAL), Salamanca, Spain.
authors.forename: Ana-María
authors.initials: AM
authors.lastname: Mateos-Díaz
authors.affiliation: Department of Infectious Diseases, Hospital Clinic of Barcelona-IDIBAPS, Barcelona, Spain.
authors.forename: Jose-Antonio
authors.initials: JA
authors.lastname: Martinez
authors.affiliation: Department of Microbiology, Hospital Clinic of Barcelona, Barcelona, Spain.
authors.forename: Manel
authors.initials: M
authors.lastname: Almela
authors.affiliation: Department of Infectious Diseases, Hospital Clinic of Barcelona-IDIBAPS, Barcelona, Spain.
authors.forename: Nazaret
authors.initials: N
authors.lastname: Cobos-Trigueros
authors.affiliation: Department of Infectious Diseases, Hospital Clinic of Barcelona-IDIBAPS, Barcelona, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Morata
authors.affiliation: Department of Infectious Diseases, Hospital Clinic of Barcelona-IDIBAPS, Barcelona, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: De-la-Calle
authors.affiliation: Department of Infectious Diseases, Hospital Clinic of Barcelona-IDIBAPS, Barcelona, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Sala
authors.affiliation: Department of Infectious Diseases, Hospital Clinic of Barcelona-IDIBAPS, Barcelona, Spain.
authors.forename: Josep
authors.initials: J
authors.lastname: Mensa
authors.affiliation: Department of Internal Medicine, University Hospital of Salamanca and Institute of Biomedical Research of Salamanca (IBSAL), Salamanca, Spain mmarcos@usal.es.
authors.forename: Miguel
authors.initials: M
authors.lastname: Marcos
authors.affiliation: Department of Infectious Diseases, Hospital Clinic of Barcelona-IDIBAPS, Barcelona, Spain.
authors.forename: Alex
authors.identifier: http://orcid.org/0000-0002-9374-0811
authors.initials: A
authors.lastname: Soriano
mesh_terms: D000081:Acetamides / Q000627:therapeutic use*; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D016470:Bacteremia / Q000188:drug therapy* / Q000382:microbiology / Q000401:mortality / Q000473:pathology; D036262:Empirical Research; D005260:Female; D006020:Glycopeptides / Q000627:therapeutic use; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000254:growth & development; D016905:Gram-Negative Bacterial Infections / Q000188:drug therapy* / Q000382:microbiology / Q000401:mortality / Q000473:pathology; D006801:Humans; D000069349:Linezolid; D016015:Logistic Models; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D016017:Odds Ratio; D023303:Oxazolidinones / Q000627:therapeutic use*; D057216:Propensity Score; D016019:Survival Analysis
chemical_list: D000081:Acetamides; D000900:Anti-Bacterial Agents; D006020:Glycopeptides; D023303:Oxazolidinones; D000069349:Linezolid