Health and economic outcomes of antibiotic resistance in Pseudomonas aeruginosa.
BACKGROUND
Antimicrobial resistance is an increasing problem.


OBJECTIVE
To examine the clinical and economic impact of antibiotic resistance in Pseudomonas aeruginosa.


METHODS
In-hospital mortality, secondary bacteremia, length of stay, and hospital charges were examined in a cohort of 489 inpatients with positive clinical cultures for P aeruginosa. One hundred forty-four had a resistant baseline P aeruginosa isolate and 30 had resistance emerge during follow-up. Multivariable and survival analytic methods were used to adjust for confounding and effects of time.


RESULTS
The overall in-hospital mortality rate was 7.6%, 7.7% in patients with a resistant isolate at baseline (relative risk [RR], 1.3; 95% confidence interval [CI], 0.6-2.8) and 27% in patients in whom resistance emerged (RR, 3.0; 95% CI, 1.2-7.8). Secondary bacteremia developed in 1.4% of patients in whom resistance did not emerge and in 14% of those in whom resistance emerged (RR, 9.0; 95% CI, 2.7-30). The median duration of hospital stay following the initial P aeruginosa isolate was 7 days. Emergence of resistance, but not baseline resistance, was significantly associated with a longer hospital stay (P<.001 and P=.71, respectively). The average daily hospital charge was $2059. Neither baseline resistance nor emergence of resistance had a significant effect on the daily hospital charge. In a matched cohort analysis, a trend was seen toward increased total charges in patients demonstrating emergence of resistance (difference, $7340; P=.14).


CONCLUSIONS
Emergence of antibiotic resistance in P aeruginosa results in severe adverse outcomes. Efforts should be directed toward early detection and prevention of emergence of antibiotic resistance.
Carmeli
Y
Y
Division of Infectious Diseases, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
Troillet
N
N
Karchmer
A W
AW
Samore
M H
MH
D000328:Adult; D000368:Aged; D016470:Bacteremia / Q000382:microbiology; D001900:Boston; D004352:Drug Resistance, Microbial; D005260:Female; D006745:Hospital Bed Capacity, 300 to 499; D017722:Hospital Charges; D017052:Hospital Mortality; D006784:Hospitals, Teaching / Q000191:economics* / Q000706:statistics & numerical data; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D011552:Pseudomonas Infections / Q000188:drug therapy* / Q000191:economics* / Q000401:mortality; D011550:Pseudomonas aeruginosa / Q000187:drug effects*; D012306:Risk