Table 1 Comparison of patients with Acinetobacter baumannii (AB) infections with matched controls

Sunenshine and colleagues, 2007 [6]

MDR Acinetobacter spp. infections in two tertiary care hospitals in Baltimore, USA

96 patients with MDR Acinetobacter infection

91 patients with susceptible Acinetobacter infection (control group 1) or 89 uninfected patients (control group 2)

For control group 1: (1) similar exposure time (preinfection length of stay within 5% of matched reference), (2) similar institution

26%

17.6%

8.4%

0.21*/2.6** (0.3–26.1)

13.3

6.7

0.04*/2.1** (1.0–4.3)

For control group 2: (1) length of stay, (2) same ward (within 30 days)

26%

11.2%

14.8%

<0.01*/6.6** (0.4–108.3)

7.3

<0.01*/4.2** (1.5–11.6)

Grupper and colleagues, 2007 [7]

Nosocomial AB bacteremia in patients in ICU, medical and surgical wards in Israel

52 patients with Acinetobacter spp. bacteremia

52 matched controlled patients

(1) Age (± 10 years), (2) sex (± 3 years), (3) primary and secondary diagnosis of ICU admission, (4) operative procedures, (5) date of admission

29/52 (55.7%)

10/52 (19.2%)

36.5% (95% CI: 27–46%)

<0.001*/4.41 (1.98–9.87)** <0.001**

Mean 11.5

Mean 6.5

0.06

Playford and colleagues, 2007 [8]

Nosocomial acquisition of carbapenem-resistant AB in general ICU in Australia

66 patients (34 infected and 32 colonized) with AB

131 patients without any AB isolation

(1) Sex, (2) age (± 3 years), (3) APACHE II score, (4) period at risk (date of admission to carbapenem-resistant AB acquisition (for cases) or to discharge (controls))

Inhospital: 15/34 (44%)

Inhospital: 16/68 (24%)

20%

0.03/adjusted^† odds ratio: 3.9 (1.4–10.7)

Median 24 (IQR: 12.5–36.5)

Median 9 (IQR: 5–13.5)

Adjusted odds ratio: 5.8 (3.3–10.4)

Kwon and colleagues, 2007 [9]

Nosocomial AB bacteremia in three tertiary care hospitals in Korea (ICU and wards)

40 patients with imipenem nonsusceptible AB bacteremia

40 patients with imipenem-susceptible AB bacteremia

1) Age (± 5 years)

(Cumulative: 5 days, 37.5%

lative: 5 days, 12.5%

25%

<0.05

NR

NR

NR

(2) Pitt bacteremia score (± 1 point)

10 days, 50%

10 days, 17.5%

32.5%

<0.05

(3) Date of admission

30 days, 57.5%

30 days, 27.5%

30%

<0.05

Robenshtok and colleagues, 2006 [10]

Nosocomial AB bacteremia and nosocomial K. pneumoniae bacteremia in a single centre in Israel

112 patients with AB bacteremia

90 patients with K. pneumoniae bacteremia

Patients with underlying conditions (comparative cohort study)

61.6%

38.9%

22.7%

0.001*/3.6 (1.5–8.39)**

NR

NR

NR