Table 2.
Number of surviving days outside the hospital at day 28 as a function of time to antibiotics in ED patients with a suspected infection in three categories of illness severity
| Crude model HR (95% CI) | Corrected model HR (95% CI) | P (Corrected model) | |
|---|---|---|---|
| PIRO group 1 to 7 | |||
| Antibiotics <1 hour (reference category) | 1 | 1 | 0.02a |
| Antibiotics 1–3 hours | 0.84 (0.66-1.06) | 1.03 (0.78-1.36) | 0.824 |
| Antibiotics >3 hours | 1.11 (0.84-1.46) | 1.46 (1.05-2.02) | 0.023 |
| Type of hospital (academic versus urban) | 0.635 (0.486-0.831) | 0.001 | |
| P score | 1.16 (1.04-1.30) | 0.008 | |
| O score | 1.03 (0.96-1.12) | 0.408 | |
| Statin use | 1.32 (1.02-1.70) | 0.033 | |
| Appropriateness of antibiotics | 0.61 (0.46-0.81) | 0.001 | |
| Amount of oxygen (L/min) | 1.01 (0.99-1.04) | 0.301 | |
| Amount of fluids (L/ED stay) | 1.23 (1.06-1.43) | 0.005 | |
| PIRO group 8 to 14 | |||
| Antibiotics <1 hour (reference category) | 1 | 1 | 0.984a |
| Antibiotics 1–3 hours | 0.85 (0.70-1.02) | 1.02 (0.83-1.25) | 0.863 |
| Antibiotics >3 hours | 0.79 (0.60-1.04) | 1.02 (0.75-1.38) | 0.910 |
| Type of hospital (academic versus urban) | 0.54 (0.44-0.66) | <0.001 | |
| P score | 1.05 (1.00-1.11) | 0.05 | |
| O score | 1.06 (1.00-1.13) | 0.037 | |
| Appropriateness of antibiotics | 0.76 (0.61-0.93) | 0.008 | |
| Amount of oxygen (L/min) | 1.02 (1.00-1.04) | 0.015 | |
| Amount of fluids (L/ED stay) | 1.03 (0.92-1.16 | 0.616 | |
| PIRO group >14 | |||
| Antibiotics <1 hour (reference category) | 1 | 1 | 0.361a |
| Antibiotics 1–3 hours | 1.00 (0.75-1.32) | 1.16 (0.86-1.58) | 0.366 |
| Antibiotics >3 hours | 0.89 (0.57-1.40) | 1.40 (0.84-2.34) | 0.194 |
| Type of hospital (academic versus urban) | 0.69 (0.50-0.96) | 0.025 | |
| P score | 1.10 (1.00-1.22) | 0.041 | |
| O score | 1.09 (1.02-1.17) | 0.017 | |
| Statin use | 0.84 (0.61-1.15) | 0.277 | |
| Antibiotics use | 1.04 (0.77-1.41) | 0.789 | |
| Appropriateness of antibiotics | 0.70 (0.51-0.95) | 0.024 | |
| Amount of oxygen (L/min) | 1.03 (1.01-1.05) | 0.014 | |
| Amount of fluids (L/ED stay) | 1.14 (1.01-1.29) | 0.042 | |
Cox regression analysis was performed with time to antibiotics divided into three categories, corrected for possible predefined confounders: PIRO score; antibiotic, β-blocker, or statin use prior to ED presentation; efficacy of antibiotics; amount of fluids (L); amount of oxygen (L/min) in the ED; and type of hospital (academic versus urban hospital). Hazard ratio >1 indicates a larger number of days outside the hospital at day 28 after ED presentation compared to the reference category of time to antibiotics within one hour. aOverall P value for categories of time to antibiotics. The P values were not used to construct the model.
CI, Confidence interval; ED, Emergency department; HR, Hazard ratio; ICU, Intensive care unit; and PIRO, Predisposition, Infection, Response, and Organ failure score (as a measure of illness severity).