Table 1.
Baseline characteristics of the derivation and validation cohorts
| Cohort, no. (%) of patients | ||
| Derivation (N = 315) | Validation (N = 276) | |
| Demographics | ||
| Age, median (IQR), years | 79 (70–85) | 76 (61–83) |
| Gender (women) | 143 (45) | 124 (45) |
| Nursing home resident | 74 (23) | 14 (5) |
| Comorbidities | ||
| Coronary artery disease | 40 (13) | 34 (12) |
| Heart failure | 59 (19) | 33 (12) |
| Diabetes mellitus | 64 (20) | 61 (22) |
| Cerebrovascular disease | 65 (20) | 51 (18) |
| Dementia | 38 (12) | 25 (9) |
| COPD | 58 (18) | 54 (20) |
| Cancer | 64 (20) | 37 (13) |
| Chronic kidney disease (eGFR < 30) | 42 (13) | 24 (9) |
| Liver disease | 15 (5) | 9 (4) |
| Charlson Comorbidity Index | 6 (4–8) | 4 (2–6) |
| Number of comorbidities | ||
| 0 | 38 (12) | 85 (30) |
| 1 | 68 (21) | 69 (25) |
| > 1 | 209 (66) | 122 (44) |
| Active smoker | 28 (18) | 67 (24) |
| Severity of Pneumonia | ||
| CURB-65 score | 2 (1–2) | 2 (1–2) |
| PSI score | 102 (84–128) | 93 (73–114) |
| PSI class I–II | 39 (12) | 70 (25) |
| III | 66 (21) | 72 (26) |
| IV | 134 (42) | 99 (36) |
| V | 75 (24) | 32 (12) |
| Vital parameters at admission | ||
| Systolic blood pressure (mmHg) | 133 ± 22 | 127 ± 23 |
| Heart rate (bpm) | 92 ± 18 | 94 ± 20 |
| Respiratory rate (median, IQR) | 16 (14–20) | 20 (16–24) |
| Body temperature (median (IQR), °C) | 37.7 (36.8–38.5) | 37.3 (36.5–38.2) |
| Arterial oxygen saturation (%) | 93 (90–96) | 92 (88–95) |
| Altered mental status at admission (%) | 67 (21) | 35 (13) |
| Bilateral involvement at Rx (%) | 65 (21) | 65 (23) |
| Laboratory data | ||
| Haemoglobin (g/L) | 12.5 ± 1.9 | 12.7 ± 1.9 |
| Haematocrit (median (IQR), %) | 37.6 (34–41) | 38.2 (35–42) |
| RDW (median (IQR), %) | 14.4 (13.6–15.9) | 14.2 (13.4–15.4) |
| eGFR (ml/min) | 65.2 ± 28 | 67.9 ± 28 |
| BUN (median (IQR), mg/dL) | 23 (16–33) | 22 (15–32) |
| C-Reactive Protein (median (IQR), mg/dL) | 68 (33–191) | 43 (21–125) |
| Procalcitonin (mg/L) | 0.27 (0.12–1.3) | 0.20 (0.1–1.0)* |
| Sodium (mEq/L) | 138.3 (135–141) | 137 (134–139) |
| Glucose (mg/dL) | 128 (109–152) | 130 (107–163) |
| Primary outcome | ||
| 18-month mortality | 102 (32) | 51 (18) |
Data are expressed as number (percentage), mean ± standard deviation or median (25–75% percentiles) as appropriate
BUN blood urea nitrogen, COPD chronic obstructive pulmonary disease, eGFR estimated glomerular filtration rate, PSI Pneumonia Severity Index, RDW red cell distribution width
*Data available for N = 187