Table 3 clinical impact of microbiological analysis of blood cultures in the pre-intervention and post-intervention study periods

Antimicrobial stewardship-beneficial change

N (%)

29 (63%)

31 (54%)

0.83

Time to change, hours, mean ± SD

49.6 ± 19.6

29.2 ± 13.3

< 0.0001

Time to appropriate antimicrobial treatment, hours, median (IQR)

Entire cohort

3.1 (0.4–21.7)

6.8 (0.9–24.5)

0.32

Only cases with an inappropriate empiric treatment

36.1 (22.7–66.4) [N = 10]

28.5 (19.8–31.1) [N = 13]

0.23

Empiric antimicrobial treatment

Appropriate treatment, N (%)

36 (78%)

44 (77%)

> 0.99

Time to treatment, hours, median (IQR)

1.3 (0-5.9)

1.7 (0-7.7)

0.73

After Gram-negative bacteremia reporting

Antimicrobial change, N (%)

20 (44%)

13 (23%)

0.03

Time to change, hours, median (IQR)

22.1 (13.5–32.6)

21 (16.5–24.9)

0.89

Appropriate treatment after change, N (%)

40 (87%)

48 (84%)

0.78

Beneficial change, N (%)

8/20

8/13

0.3

After bacterial identification

Antimicrobial change, N (%)

3 (7%)

3 (5%)

> 0.99

Time to change, hours, median (IQR)

35.1 (22.5–45.2)

21 (16.5–30.9)

0.2

Appropriate treatment after change, N (%)

40 (87%)

52 (91%)

0.53

Beneficial change, N (%)

2/3

3/3

> 0.99

After antimicrobial susceptibility results

Antimicrobial change, N (%)

25 (57%)

28 (60%)

0.83

Time to change, hours, median (IQR)

53.8 (45.6–71.4)

31.1 (26.4–39.4)

< 0.0001

Appropriate treatment after change, N (%)

46 (100%)

57 (100%)

> 0.99

Beneficial change, N

25/28

22/28

0.47

Mortality, n (%)

12 (26%)

10 (18%)

0.34

Attributable mortality, n (%)

9 (21%)

9 (16%)

0.61

Length of stay, days, median (IQR)

8 (4–10)

7 (4-11.5)

0.92

Antimicrobial treatment duration, days, median (IQR)

8 (5–11)

10 (7–14)

0.007

Re-admission within 30 days, n (%)

8/34

7/47

0.39

 C. difficile infection within 90 days, n (%)

0

0

NA