Table 1.
Baseline characteristics of the study cohort
| Characteristic | Entire cohort | Non-survivors | Survivors | P value | Hospitalised | Non-hospitalised | P value | ICU admission | Non-ICU admission | P value |
|---|---|---|---|---|---|---|---|---|---|---|
| Number of patients | 1641 | 547 | 1094 | 861 | 780 | 246 | 1395 | |||
| Age, years | 73 (62–79) | 75 (66–81) | 73 (60–78) | <0.001 | 74 (65–80) | 72 (59–78) | <0.001 | 75 (68–81) | 73 (61–79) | <0.001 |
| Male sex, % | 59 | 58 | 59 | 0.48 | 57 | 61 | 0.12 | 57 | 59 | 0.61 |
| Co-morbidities, % | ||||||||||
| COPD | 34 | 36 | 32 | 0.10 | 36 | 31 | 0.01 | 43 | 32 | 0.001 |
| CVD | 28 | 30 | 26 | 0.07 | 30 | 26 | 0.13 | 30 | 27 | 0.33 |
| Stroke | 12 | 14 | 11 | 0.08 | 12 | 12 | 0.79 | 13 | 12 | 0.66 |
| Tumour | 9 | 11 | 8 | 0.04 | 10 | 8 | 0.16 | 11 | 9 | 0.32 |
| Renal | 5 | 6 | 4 | 0.08 | 6 | 4 | 0.22 | 7 | 5 | 0.26 |
| Liver | 8 | 9 | 8 | 0.25 | 8 | 8 | 0.62 | 10 | 8 | 0.19 |
| DM | 15 | 13 | 16 | 0.13 | 17 | 14 | 0.06 | 17 | 15 | 0.38 |
| Vital signs | ||||||||||
| MAP, mmHg | 80 (67–93) | 70 (54–83) | 84 (73–97) | <0.001 | 77 (60–90) | 83 (71–97) | <0.001 | 67 (50–82) | 82 (70–95) | <0.001 |
| Respiratory rate, breaths/minute | 27 (24–32) | 28 (24–32) | 26 (24–32) | 0.01 | 28 (24–32) | 26 (24–32) | 0.09 | 30 (24–32) | 26 (24–32) | 0.003 |
| Temperature, °C | 36.8 (36.2–38.2) | 36.8 (36.2–38.2) | 36.8 (36.2–38.1) | 0.83 | 36.8 (36.2–38.2) | 36.8 (36.2–38.1) | 0.65 | 37 (36.2–38.2) | 36.8 (36.2–38.1) | 0.62 |
| Heart rate, beats/minute | 110 (98–126) | 110 (99–126) | 110 (97–125) | 0.20 | 110 (98–128) | 110 (98–124) | 0.22 | 110 (98–126) | 110 (98–126) | 0.99 |
| Mental confusion, % | 28 | 46 | 20 | <0.001 | 37 | 19 | <0.001 | 66 | 22 | <0.001 |
| Laboratory results | ||||||||||
| WBC, ×109/L | 11.2 (7.7–15.6) | 11.0 (7.6–15.1) | 11.2 (7.8–15.6) | 0.48 | 11.2 (7.7–15.5) | 11.3 (7.7–15.7) | 0.75 | 11.4 (7.6–16) | 11.2 (7.7–15.5) | 0.71 |
| PCT, ng/ml | 1.1 (0.9–3.4) | 1.3 (0.9–9.4) | 1.1 (0.9–3.4) | <0.001 | 1.1 (0.9–3.4) | 1.1 (0.9–3.4) | 0.50 | 1.2 (0.9–3.7) | 1.1 (0.9–3.4) | 0.15 |
| PaO2, mmHg | 75 (59–94) | 71 (57–89) | 77 (60–96) | <0.001 | 74 (59–92) | 76 (59–96) | 0.28 | 69 (55–86) | 77 (60–95) | <0.001 |
| Platelets, ×109/L | 184 (135–243) | 185 (136–243) | 183 (134–244) | 0.91 | 186 (136–243) | 183 (134–243) | 0.81 | 188 (142–246) | 183 (134–242) | 0.73 |
| Creatinine, μmol/L | 100 (75–148) | 106 (78–170) | 98 (74–136) | <0.001 | 102 (77–157) | 98 (73–136) | 0.02 | 134 (98–228) | 96 (72–134) | <0.001 |
| Bilirubin, μmol/L | 12.3 (8.3–18.6) | 13.1 (8.1–19.3) | 12.0 (8.1–18.3) | 0.04 | 12.2 (8.2–19) | 12.5 (8.3–18.3) | 0.94 | 12.2 (8.2–18.7) | 12.3 (8.3–18.5) | 0.63 |
| Positive sputum culture | 378/1132 (33 %) | 143/394 (36 %) | 235/738 (32 %) | 0.13 | 209/583 (36 %) | 169/549 (31 %) | 0.07 | 73/187 (39 %) | 305/945 (32 %) | 0.07 |
| Lactate, mmol/L | 2.6 (1.0–5.1) | 5.4 (3.1–8.1) | 1.6 (0.8–3.3) | <0.001 | 4.4 (2.5–7.0) | 1.2 (0.6–2.5) | <0.001 | 8.5 (6.6–11.7) | 2.1 (0.9–4.0) | <0.001 |
| Multi-lobar opacities, % | 40 | 47 | 37 | <0.001 | 42 | 38 | 0.07 | 53 | 38 | <0.001 |
| PSI | 124 ± 40 (n = 578) | 144 ± 36 (n = 199) | 113 ± 38 (n = 379) | <0.001 | 137 ± 38 (n = 278) | 111 ± 38 (n = 300) | <0.001 | 156 ± 37 (n = 92) | 117 ± 38 (n = 486) | <0.001 |
| APACHE II | 16 (12–21) | 20 (15–26) | 15 (11–19) | <0.001 | 18 (14–23) | 15 (11–18) | <0.001 | 22 (17–28) | 16 (11–20) | <0.001 |
| CRB-65 | 2 (1–2) | 2 (1–3) | 1 (1–2) | <0.001 | 2 (1–2) | 1 (1–2) | <0.001 | 2 (2–3) | 1 (1–2) | <0.001 |
| CRB | 1 (0–1) | 1 (1–2) | 1 (0–1) | <0.001 | 1 (0–2) | 1 (0–1) | <0.001 | 1 (1–2) | 1 (0–1) | <0.001 |
| qSOFA | 1 (1–2) | 2 (1–2) | 1 (1–1) | <0.001 | 1 (1–2) | 1 (1–2) | <0.001 | 2 (1–2) | 1 (1–2) | <0.001 |
| 28-day mortality (%) | 33 | – | – | – | 54 | 11 | <0.001 | 85 | 24 | <0.001 |
Abbreviations: APACHE Acute Physiology and Chronic Health Evaluation, COPD chronic obstructive pulmonary disease, CRB confusion, respiratory rate ≥30/minute, systolic blood pressure <90 mmHg or diastolic blood pressure ≤60 mmHg, CRB-65 confusion, respiratory rate ≥30/minute, systolic blood pressure <90 mmHg or diastolic blood pressure ≤60 mmHg, age ≥65 years, CVD cardiovascular disease, DM diabetes mellitus, ICU intensive care unit, MAP mean arterial pressure, PaO 2 arterial oxygen pressure, PCT procalcitonin, PSI Pneumonia Severity Index, qSOFA quick Sepsis-related Organ Failure Assessment, WBC white blood cells
Skewed distributed data are expressed as medians and quartiles. Normal distributed data are expressed as mean ± standard deviation