Table 2.
Derivation cohort characteristics with regards to 28-day mortality
| Patient characteristics | Total patient cohort (N = 1175) | Survivors (N = 1091) | Non-survivors (N = 84) | p value |
|---|---|---|---|---|
| Demographics | ||||
| Age (years) (mean, SD) | 63.3 (20.9) | 62.0 (20.9) | 79.7 (11.6) | < 0.001 |
| Male gender (N, %) | 592 (50.4%) | 543 (49.8%) | 49 (58.3%) | 0.130 |
| Disposition | ||||
| Hospital admission (N, %) | 915 (77.9%) | 831 (76.2%) | 84 (100.0%) | < 0.001 |
| Hospital length of stay (days) (median, Q1–Q3) | 4 [1–9] | 4 [1–9] | 11 [5–17] | < 0.001 |
| ICU admission (N, %) | 32 (2.7%) | 18 (1.6%) | 14 (16.7%) | < 0.001 |
| Comorbidities | ||||
| Cardiovascular disease (N, %) | 363 (30.9%) | 316 (29.0%) | 47 (56.0%) | < 0.001 |
| Diabetes (N, %) | 216 (18.4%) | 196 (18.0%) | 20 (23.8%) | 0.183 |
| Immunodeficiency (N, %) | 64 (5.4%) | 56 (5.1%) | 8 (9.5%) | 0.088 |
| Liver disease (N, %) | 31 (2.6%) | 28 (2.6%) | 3 (3.6%) | 0.580 |
| Malignancy (N, %) | 228 (19.4%) | 198 (18.1%) | 30 (35.7%) | < 0.001 |
| Neurological disorders (N, %) | 135 (11.5%) | 116 (10.6%) | 19 (22.6%) | < 0.001 |
| Respiratory disease (N, %) | 378 (32.2%) | 344 (31.5%) | 34 (40.5%) | 0.091 |
| Renal disease (N, %) | 82 (7.0%) | 68 (6.2%) | 14 (16.7%) | < 0.001 |
| Infectious source | ||||
| Bone and Joint (N, %) | 13 (1.1%) | 13 (1.2%) | 0 (0.0%) | 0.315 |
| Cardiac (N, %) | 6 (0.5%) | 5 (0.5%) | 1 (1.2%) | 0.364 |
| Central nervous system (N, %) | 13 (1.1%) | 10 (0.9%) | 3 (3.6%) | 0.025 |
| Fever of unknown origin (N, %) | 98 (8.3%) | 87 (8.0%) | 11 (13.1%) | 0.100 |
| Foreign object (N, %) | 5 (0.4%) | 4 (0.4%) | 1 (1.2%) | 0.264 |
| Intra-abdominal (N, %) | 158 (13.4%) | 153 (14.0%) | 5 (6.0%) | 0.007 |
| Respiratory—lower (N, %) | 413 (35.1%) | 369 (33.8%) | 44 (52.4%) | < 0.001 |
| Respiratory—upper (N, %) | 85 (7.2%) | 85 (7.8%) | 0 (0.0%) | 0.008 |
| Skin and soft tissue (N, %) | 96 (8.2%) | 89 (8.2%) | 7 (8.3%) | 0.901 |
| Surgical-related (N, %) | 10 (0.9%) | 10 (0.9%) | 0 (0.0%) | 0.379 |
| Urogenital (N, %) | 278 (23.7%) | 266 (24.4%) | 12 (14.3%) | 0.041 |
| Microbiological findings | ||||
| Blood cultures taken (N, %) | 888 (75.6%) | 823 (75.4%) | 65 (77.4%) | 0.689 |
| Positive blood cultures (N, %) | 227 (19.3%) | 205 (18.8%) | 22 (26.2%) | 0.099 |
| Gram-positive bacteria (N, %) | 120 (10.2%) | 108 (9.9%) | 12 (14.3%) | 0.201 |
| Gram-negative bacteria (N, %) | 179 (15.2%) | 166 (15.2%) | 13 (15.5%) | 0.949 |
| Fungal cultures (N, %) | 9 (0.8%) | 8 (0.7%) | 1 (1.2%) | 0.643 |
| Viral PCR (N, %) | 40 (3.4%) | 39 (3.6%) | 1 (1.2%) | 0.246 |
| Other (N, %) | 9 (0.8%) | 8 (0.7%) | 1 (1.2%) | 0.830 |
| Biomarkers and clinical scores | ||||
| MR-proADM (nmol/L) (median, Q1–Q3) | 1.09 [0.69–1.71] | 1.02 [0.67–1.59] | 2.65 [1.81–4.67] | < 0.001 |
| PCT (ng/mL) (median, Q1–Q3) | 0.17 [0.07–0.77] | 0.16 [0.07–0.61] | 0.94 [0.23–3.12] | < 0.001 |
| Lactate (mmol/L) (median, Q1–Q3) | 1.60 [1.14–2.30] | 1.55 [1.10–2.23] | 2.40 [1.50–3.50] | < 0.001 |
| CRP (mg/L) (median, Q1–Q3) | 32 [10–120] | 30 [10–112] | 102 [28–178] | < 0.001 |
| SIRS (points) (median, Q1–Q3) | 2 [1–3] | 2 [1–3] | 3 [2–3] | < 0.001 |
| SOFA (points) (median, Q1–Q3) | 2 [0–3] | 1 [0–3] | 4 [2–6] | < 0.001 |
| qSOFA (points) (median, Q1–Q3) | 0 [0–1] | 0 [0–1] | 1 [1–2] | < 0.001 |
| NEWS (points) (median, Q1–Q3) | 4 [2–7] | 4 [2–7] | 8 [5–10] | < 0.001 |
| CRB-65 (points) (median, Q1–Q3) | 1 [0–2] | 1 [0–1] | 2 [1–2] | < 0.001 |
Values expressed in percentages (%) indicate either the proportion of the total patient cohort, surviving or non-surviving patients at 28 days for each variable, where applicable. Data are presented as mean (standard deviation, SD) or median [first quartile (Q1)–third quartile (Q3)] where appropriate. The chi-square (χ2) test was used to determine significance between surviving and non-surviving patients for categorical variables, Student’s t test for the variable of age, and Mann-Whitney U test for hospitalisation duration, biomarker and clinical score variables. CRB-65 Severity score for community-acquired pneumonia, CRP C-reactive protein, ICU intensive care unit, MR-proADM mid-regional proadrenomedullin, N number, NEWS National Early Warning Score, PCR polymerase chain reaction, PCT procalcitonin, qSOFA quick Sequential Organ Failure Assessment, SIRS systemic inflammatory response syndrome, SOFA Sequential Organ Failure Assessment