Clinical and economic impact of meropenem resistance in Pseudomonas aeruginosa-infected patients.
The emergence of carbapenem resistance has had a significant impact on both clinical and economic outcomes.



A retrospective, observational cohort study was performed in a 433-bed tertiary care medical center. The cohort was established from all inpatients with Pseudomonas aeruginosa-positive cultures over a 3-year period. Two multivariate models were developed: a logistic regression model to evaluate the primary outcome of in-hospital mortality and a linear regression model to evaluate the secondary outcome of total hospital cost.



The adjusted odds ratio for in-hospital mortality among patients with meropenem-resistant isolates was 2.89 (95% confidence interval [CI], 1.15-7.28). There were significantly more deaths in the meropenem-resistant group (28.1% vs 8.9%, P = .003). Patients with meropenem-resistant P aeruginosa experienced a 4-day increase in median length of stay versus those in the meropenem-susceptible group (14 vs 9 days, P = .004). Likewise, the percentage of patients who required intensive care unit (ICU) admission increased from 42% to 81.3% (P <.001). Meropenem resistance was also associated with a significant increase in total hospital cost by a factor of 1.42 among patients who were not admitted to the ICU (95% CI, 1.03-1.95).



Our results demonstrate that meropenem resistance was a significant predictor of in-hospital mortality. Carbapenem resistance also resulted in a significant increase in hospital cost, but only among patients who were not admitted to the ICU.
Department of Pharmacy Services, Saint Joseph Hospital, Lexington, KY. Electronic address: juddwr@sjhlex.org.
William R
WR
Judd
Department of Pharmacy Services, Saint Joseph Hospital, Lexington, KY.
Patrick D
PD
Ratliff
Division of Pharmaceutical Outcomes and Policy, The University of North Carolina at Chapel Hill, Chapel Hill, NC.
Ryan P
RP
Hickson
Department of Infection Control, Saint Joseph Hospital, Lexington, KY.
Dana M
DM
Stephens
Division of Infectious Diseases, Saint Joseph Hospital, Lexington, KY; Lexington Infectious Disease Consultants, Lexington, KY.
Charles A
CA
Kennedy
D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D005260:Female; D017721:Hospital Costs; D006801:Humans; D008297:Male; D000077731:Meropenem; D008875:Middle Aged; D011552:Pseudomonas Infections / Q000191:economics / Q000382:microbiology* / Q000401:mortality*; D011550:Pseudomonas aeruginosa / Q000187:drug effects*; D012189:Retrospective Studies; D016019:Survival Analysis; D062606:Tertiary Care Centers; D013845:Thienamycins / Q000494:pharmacology*; D016896:Treatment Outcome; D018440:beta-Lactam Resistance
D000900:Anti-Bacterial Agents; D013845:Thienamycins; D000077731:Meropenem
Pseudomonas aeruginosa; carbapenem resistance; hospital cost; multidrug resistance; multivariate logistic regression