TABLE 1.

Characteristics and exposures of patients with MDR P. aeruginosa and their matched controlse

CharacteristicCases (n = 82)Controls (n = 82)OR (95% CI)P value
Demographics
    Age (yr)a (mean ± SD)65 ± 1763 ± 201.0 (0.9-1.02)0.5
    Male gender [no. (%)]50 (60)41 (50)1.5 (0.8-2.9)0.16
    No. of comorbidities [mean (SD)]1.2 (0.9)1.3 (0.8)0.8 (0.6-1.2)0.5
Exposures prior to MDR P. aeruginosa isolationb
    Transfer from institution [no. (%)]11 (13)1 (1)11.1 (1.4-85)0.02
    Home antibiotic Rx [no. (%)]13 (15)5 (6)2.6 (0.9-7.2)0.06
    ICU stay [no. (%)]32 (39)16 (19)17 (2.3-127)0.006
    Surgery [no. (%)]43 (52)37 (45)1.5 (0.7-3.2)0.2
    Immunosuppressive therapy [no. (%)]c7 (8)11 (13)0.5 (0.1-1.6)0.2
    Foley catheter [no. (%)]63 (76)41 (50)6.5 (2.2-18.6)<0.001
    Central venous line [no. (%)]39 (47)26 (31)3.8 (1.4-10.1)0.008
    Dialysis [no. (%)]4 (4)5 (6)0.7 (0.1-3.3)0.7
    Mechanical ventilation [no. (%)]42 (51)17 (20)27 (3.6-198.6)0.001
Severity of illnessd
    Vasopressor treatment [no. (%)]23 (28)11 (13)4.0 (1.3-11.9)0.01
    Bedridden [no. (%)]56 (68)38 (46)3.4 (1.4-7.9)0.004
    McCabe score,a Nonfatal [no. (%)]50 (61)45 (54)1.1 (0.6-1.9)0.6
Antibiotic treatment
    No. of patients treatedc (%)64 (78)53 (64)3.2 (1.3-7.9)0.014
    No. of antibiotics (mean ± SD)2.3 ± 1.61.7 ± 1.51.4 (1.1-1.9)0.006
    Agent [no. (%)]a
        Penicillin63 (76)50 (60)3.1 (1.2-7.9)0.01
        Cephalosporin (narrow spectrum)3 (3)2 (2)1.5 (0.2-8.9)0.6
        Cephalosporin (extended spectrum)15 (18)14 (17)1.0 (0.4-2.4)0.8
        Cephalosporin (broad spectrum)26 (31)15 (18)2.1 (0.9-4.4)0.05
        Cephalosporin (“fourth generation”)f3 (3)3 (3)1.8 (0.2-4.9)1.0
        Quinolones11 (13)6 (7)1.8 (0.6-4.9)0.2
Antipseudomonal drugs48 (58)31 (37)5.2 (1.8-15.2)0.002
    Carbapenems6 (7)6 (7)1.0 (0.2-3.9)1.0
    Aminoglycosides30 (36)18 (21)2.7 (1.1-6.4)0.02
    Vancomycin6 (7)7 (8)0.8 (0.2-2.7)0.7
    Macrolides6 (7)4 (4)1.5 (0.4-5.3)0.5
    Chloramphenicol5 (6)3 (3)1.6 (0.3-6.9)0.4
    Metronidazole6 (7)9 (10)0.5 (0.1-1.9)0.3
    Sulfamides2 (2)01.0
  • a Continuous variable.

  • b Exposures that occurred between hospital admission and inclusion in the study.

  • c Immunosuppressive therapy referred to chemotherapy within 3 weeks of study entry or treatment with at least 20 mg of prednisone daily for at least 2 weeks before study entry (16).

  • d Severity of illness 48 hours before inclusion in the study.

  • e Matched univariate analysis. CI, confidence interval; Rx, prescription.

  • f Fourth generation refers to cefepime.