Table 3.
Association of strain index with hospital LOS in “usually-ward” and “usually-ICU” subgroups of patients with sepsis and ARF
| Cohort | Quantile Regression Estimate (Bootstrap 95% CI)*; P Value |
|
|---|---|---|
| Usually Ward† | Usually ICU‡ | |
| Death set as 95th-percentile LOS§ | ||
| Sepsis‖ | −0.07 (−0.06 to 0.46); 0.58 | −0.35 (−1.06 to 2.67); 0.70 |
| ARF¶ | −0.06 (−0.23 to 0.17); 0.58 | −0.07 (−1.01 to 0.77); 0.89 |
| Death set as 99th-percentile LOS** | ||
| Sepsis | −0.07 (−0.02 to 0.50); 0.55 | −0.55 (−2.46 to 10.41); 0.84 |
| ARF | −0.06 (−0.24 to 0.19); 0.55 | −0.19 (−4.35 to 2.33); 0.91 |
| Death set as longest observed LOS†† | ||
| Sepsis | −0.07 (−0.03 to 0.49); 0.56 | 10.36 (−24.87 to 70.25); 0.64‡‡ |
| ARF | −0.06 (−0.24 to 0.20); 0.54 | 1.27 (−35.27 to 20.43); 0.92‡‡ |
Definition of abbreviations: 95% CI = 95% confidence interval; ARF = acute respiratory failure; ICU = intensive care unit; LOS = length of stay.
Models were adjusted for patient-level covariates of age, sex, ethnicity, race, insurance, Laboratory-based Acute Physiology Score version 2, Comorbidity Point Score version 2, and hospital.
Based on 5,000 runs.
Sepsis patients with Sequential (Sepsis-related) Organ Failure Assessment = 0 and no mechanical ventilation or vasopressors in the emergency department (88.9% admitted to the ward). ARF patients with Laboratory-based Acute Physiology Score version 2 ≤ 50 and no mechanical ventilation or vasopressors in the emergency department (88.5% admitted to the ward).
Mechanical ventilation and vasopressors in the emergency department (99.5% of patients with sepsis and 99.2% of patients with ARF admitted to the ICU).
For the usually-ward group, the 95th-percentile LOS = 12.7 days for sepsis and 10.8 days for ARF; for the usually-ICU group, the 95th-percentile LOS = 31.2 days for sepsis and 29.7 days for ARF.
n = 6,562 for the usually-ward group, and n = 2,169 for the usually-ICU group.
n = 3,571 for the usually-ward group, and n = 3,150 for the usually-ICU group.
For the usually-ward group, the 99th-percentile LOS = 26.5 days for sepsis and 25.1 days for ARF; for the usually-ICU group, the 99th-percentile LOS = 58.5 days for sepsis and 56.6 days for ARF.
For the usually-ward group, the longest observed LOS = 288.9 days for sepsis and 83.7 days for ARF; for the usually-ICU group, the longest observed LOS = 341.0 days for sepsis and 341.0 days for ARF.
Divergent point estimates in these analyses are due to the presence of outlier patients with extremely long hospital LOS in the usually-ICU subgroup that then serve as the LOS assignment for deaths in the “placement-of-death” approach.