Table 2. Primary and Secondary Outcomes.
| Outcome | No. (%) | P value | |
|---|---|---|---|
| Gram stain–guided group (n = 103) | Guideline-based group (n = 103) | ||
| Primary outcome | |||
| Clinical response rate | 79 (76.7) | 74 (71.8) | <.001a |
| Completion of antibiotic therapy within 14 db | 98 (95.1) | 94 (91.3) | NA |
| Improvement or lack of progression of baseline radiographic findingsb | 85 (82.5) | 78 (75.7) | NA |
| Resolution of signs and symptoms of pneumoniab | 87 (84.5) | 85 (82.5) | NA |
| Lack of antibiotic agent readministrationb | 85 (82.5) | 85 (82.5) | NA |
| Secondary outcomes | |||
| 28-d mortality | 14 (13.6) | 18 (17.5) | .44 |
| 28-d ventilator-free days, median (IQR) | 22 (15-24) | 22 (18-25) | .21 |
| 28-d ICU-free days, median (IQR) | 19 (15-22) | 20 (16-23) | .42 |
| Administration of antibiotic therapy | |||
| Antipseudomonal agents | 72 (69.9) | 103 (100) | <.001 |
| Anti-MRSA agents | 63 (61.2) | 103 (100) | <.001 |
| Coverage rate of initial antibiotic therapy | 89 (86.4) | 95 (92.2) | .18 |
| Escalationb | 7 (6.8) | 1 (1.0) | .03 |
| De-escalation | 67 (65.0) | 79 (76.7) | .07 |
| Antibiotic therapy days until de-escalation, median (IQR) | 3 (2-4) | 3 (2-4) | .22 |
| Antibiotic therapy days, median (IQR) | 8 (7-11) | 8 (7-11) | .09 |
Abbreviations: ICU, intensive care unit; MRSA, methicillin-resistant Staphylococcus aureus.
a
The noninferiority of the primary outcome was analyzed using the normal theory test for binomial proportions.
b
Added post hoc.