Table 3

Microbiological characteristics of the study cohort


Control group (n = 7,626)
Corticosteroid exposure group (n = 2,632)
P

Microbiology



     Number of patients with cultures
3,185 (42)
1,764 (67)
0.0001
     Infection confirmed
1,785 (23)
1,215 (46)
0.0001
Location of infection
n = 1,785
n = 1,215

     Pulmonary
578 (32)
489 (40)
0.0001
     Abdomen
197 (11)
147 (12)
0.4
     Genital–urinary tract
703 (39)
425 (35)
0.02
     Bloodstream
500 (28)
376 (31)
0.09
     Soft tissue
165 (9)
90 (7)
0.08
     Vascular catheters
156 (9)
158 (13)
0.0002
     Skeletal
54 (3)
24 (2)
0.08
     Central nervous system
46 (3)
47 (4)
0.05
     Head and neck
17 (1)
21 (2)
0.07
     Other
16 (1)
9 (1)
0.7
Temporal characteristics
n = 1,785
n = 1,215

     Infection episode ≤ 2 days after admission
1,228 (69)
820 (67)
0.5
     Infection episode >2 days after admission
883 (49)
669 (55)
0.003
     Recurrent infectiona
633 (35)
521 (43)
0.0001
     Day of last infection episode during a hospital stay
2 (0–13)
3 (0–19)
0.003
     Interval between first and last infection episodes (days)
0 (0–10)
0 (0–15)
0.0001
     Interval between first and last infection episodes >2 days
434 (24)
402 (33)
0.0001
Types of microorganisms (culture or microscopy)
n = 1,785
n = 1,215

     Bacterial



          Gram-positive cocci
1,255 (70)
903 (74)
0.02
          Gram-negative bacilli
744 (42)
487 (40)
0.4
          Other types of bacillib
299 (17)
221 (18)
0.3
          Anaerobesc
182 (10)
112 (9)
0.4
          Gram-negative cocci
66 (4)
38 (3)
0.4
     Fungal
404(23)
508 (42)
0.0001
Number of types of microorganisms per location
1 (1–4)
2 (1–6)
0.0001
     Polymicrobial infectiond
838 (47)
683 (56)
0.0001

Data presented as median (10–90% percentiles) or actual numbers (percentage). Cultures included blood, sputum, urine, normally sterile body fluid or tissue. aTwo or more infection episodes during a hospital stay. blisteria, Corynebacteria, Actinomyces, bacilli Sp., Legionella and Mycobacterial species; cClostridia, Bacteroids, Peptostreptococci, and Peptococci species.. dTwo or more types of organisms present at the same location site of infection.

Rady et al. Critical Care 2006 10:R101   doi:10.1186/cc4971