TABLE 2.
Proportion of positive blood cultures with low- and high-confidence identification at different time points
| Score | Time point (h) | Gram-negative rods (n = 63) |
Gram-positive cocci (n = 124) |
|||||
|---|---|---|---|---|---|---|---|---|
| No. (%) with identification on: |
P value | No. (%) with identification on: |
P value | |||||
| Columbia blood agar | MacConkey agar | Chocolate agar | Columbia blood agar | Chocolate agar | ||||
| ≥1.7 | 2 | 55 (87) | 56 (89) | 50 (79) | 0.3 | 36 (29.0) | 23 (18.5) | 0.05 |
| 3 | 60 (95) | 62 (98) | 60 (95) | 0.5 | 85 (68.6) | 66 (53.2) | 0.01 | |
| 4 | 62 (98) | 63 (100) | 62 (98) | NA | 107 (86.3) | 92 (74.2) | 0.02 | |
| 5 | 62 (98) | 63 (100) | 62 (98) | NA | 116 (93.6) | 111 (89.5) | 0.25 | |
| 6 | 62 (98) | 63 (100) | 62 (98) | NA | 120 (96.8) | 116 (93.6) | 0.24 | |
| 24 | 63 (100) | 63 (100) | 63 (100) | NA | 121 (97.6) | 120 (96.8) | 0.7 | |
| ≥2 | 2 | 41 (65) | 49 (78) | 36 (57) | 0.047 | 0 (0) | 0 (0) | NA |
| 3 | 58 (92) | 61 (97) | 58 (92) | 0.45 | 9 (7.3) | 7 (5.7) | 0.6 | |
| 4 | 62 (98) | 63 (100) | 62 (98) | NA | 43 (34.7) | 33 (26.6) | 0.17 | |
| 5 | 62 (98) | 63 (100) | 62 (98) | NA | 81 (65.3) | 63 (50.8) | 0.02 | |
| 6 | 62 (98) | 63 (100) | 62 (98) | NA | 103 (83.1) | 90 (72.6) | 0.47 | |
| 24 | 63 (100) | 63 (100) | 62 (98) | NA | 111 (89.5) | 106 (85.5) | 0.34 | |