Table 1.
Baseline Characteristics of the Study Population
| Characteristics | SIRI | P value | ||
|---|---|---|---|---|
| <1.6 | 1.6–3.8 | >3.8 | ||
| Number of patients | 817 | 816 | 817 | |
| Age, years | 67.6 ± 15.7 | 68.0 ± 16.1 | 68.9 ± 15.2 | 0.247 |
| Sex, n (%) | <0.001 | |||
| Female | 440 (53.9) | 375 (46.0) | 354 (43.3) | |
| Male | 377 (46.1) | 441 (54.0) | 463 (56.7) | |
| Ethnicity, n (%) | <0.001 | |||
| Black | 578 (70.7) | 630 (77.2) | 632 (77.4) | |
| White | 100 (12.2) | 49 (6.0) | 40 (4.9) | |
| Other | 139 (17.0) | 137 (16.8) | 145 (17.7) | |
| Vital signs | ||||
| Heart rate, beats/minute | 78.4 ± 15.2 | 79.1 ± 14.5 | 84.2 ± 16.1 | <0.001 |
| SBP, mmHg | 129.9 ± 17.6 | 130.5 ± 17.6 | 127.2 ± 18.3 | <0.001 |
| DBP, mmHg | 63.3 ± 10.6 | 64.1 ± 11.7 | 62.8 ± 11.3 | <0.001 |
| MAP, mmHg | 83.1 ± 11.1 | 83.6 ± 11.7 | 81.7 ± 11.9 | <0.001 |
| Respiratory rate, times/minute | 18.0 ± 3.3 | 18.2 ± 3.6 | 19.4 ± 4.1 | <0.001 |
| Temperature, °C | 36.8 ± 0.6 | 36.9 ± 0.6 | 37.0 ± 0.7 | <0.001 |
| SpO2, % | 97.6 ± 1.8 | 97.2 ± 3.1 | 97.4 ± 2.6 | 0.140 |
| Laboratory parameters | ||||
| SIRI, 109/L | 0.9 ± 0.4 | 2.6 ± 0.6 | 10.9 ± 14.2 | <0.001 |
| Neutrophil, % | 67.9 ± 15.9 | 81.6 ± 8.0 | 85.9 ± 8.4 | <0.001 |
| Monocyte, % | 4.0 ± 2.3 | 3.9 ± 2.0 | 4.6 ± 3.6 | <0.001 |
| Lymphocyte, % | 23.8 ± 12.2 | 12.5 ± 4.9 | 7.1 ± 3.4 | <0.001 |
| White blood cell counts, 109/L | 8.9 ± 11.1 | 11.0 ± 3.4 | 16.5 ± 13.9 | <0.001 |
| Platelet counts, 109/L | 226.5 ± 103.7 | 243.9 ± 95.6 | 260.8 ± 123.1 | <0.001 |
| Glucose, mg/dL | 138.7 ± 57.1 | 151.5 ± 65.6 | 163.8 ± 68.3 | 0.001 |
| Blood urea nitrogen, mg/dl | 22.1 ± 15.9 | 22.5 ± 16.0 | 27.3 ± 21.9 | <0.001 |
| Anion gap, mg/dl | 15.0 ± 3.4 | 15.3 ± 3.3 | 16.3 ± 3.9 | <0.001 |
| Comorbidities, n (%) | ||||
| Atrial fibrillation | 208 (25.5) | 239 (29.3) | 251 (30.7) | 0.051 |
| CAD | 148 (18.1) | 147 (18.0) | 149 (18.2) | 0.993 |
| Liver disease $ | 21 (2.6) | 16 (2.0) | 26 (3.2) | 0.296 |
| Respiratory failure | 168 (20.6) | 219 (26.8) | 297 (36.4) | <0.001 |
| Pneumonia | 123 (15.1) | 177 (21.7) | 253 (31.0) | <0.001 |
| Scoring systems | ||||
| SOFA | 3.4 ± 2.7 | 3.5 ± 2.6 | 4.4 ± 3.1 | <0.001 |
| SAPSII | 34.8 ± 13.3 | 34.9 ± 13.0 | 41.0 ± 14.2 | <0.001 |
| GCS | 12.9 ± 3.2 | 12.7 ± 3.3 | 12.3 ± 3.8 | 0.003 |
| APSIII | 40.8 ± 19.7 | 40.2 ± 19.2 | 47.8 ± 22.6 | |
| Clinical outcomes, n (%) | ||||
| 30-day mortality | 141 (17.3) | 161 (19.7) | 235 (28.8) | <0.001 |
| 90-day mortality | 173 (21.2) | 201 (24.6) | 285 (34.9) | <0.001 |
| One-year mortality | 219 (26.8) | 242 (29.7) | 332 (40.6) | <0.001 |
| In-hospital mortality | 163 (20.0) | 190 (23.3) | 271 (33.2) | <0.001 |
| Sepsis | 193 (23.6) | 232 (28.4) | 330 (40.4) | <0.001 |
Notes: SIRI is calculated using the counts of peripheral venous blood neutrophils (N), monocytes (M), and lymphocytes (L) as follows: SIRI=N*M/L; Data were presented as the mean ± SD and n.
Abbreviations: SIRI, systemic inflammation response index; SBP, systolic blood pressure; DBP, diastolic blood pressure; MAP, mean arterial pressure; SpO2, pulse oximetry-derived oxygen saturation; CAD, coronary artery disease; SOFA, sequential organ failure assessment; SAPS II, simplified acute physiology score II; GCS, Glasgow Coma Scale; APSIII, Antiphospholipid syndrome.