Table 1.
Baseline characteristics and clinical course.
| CAP patients | Controls | |
|---|---|---|
| n | 57 | 26 |
| Demographics | ||
| Age, years (median [IQR]) | 68 [58, 76] | 49 [38, 61] |
| Male sex, n (%) | 32 (56.1) | 17 (65.4) |
| Body mass index (median [IQR]) | 26.3 [23.2, 31.0] | 23.8 [22.0, 25.4] |
| Current smoker, n (%) | ||
| Yes | 16 (28.1) | 4 (15.4) |
| No | 36 (63.2) | 22 (84.6) |
| Unknown | 5 (8.8) | 0 (0.0) |
| Length of symptoms, days (median [IQR]) | 4 [3, 7] | |
| Comorbidities | ||
| Charlson comorbidity index, (median [IQR]) | 5 [3, 6] | 3 [2, 4] |
| Cardiac disease, n (%) | 34 (59.6) | 10 (38.5) |
| of which medicated hypertension, n (%) |
23 (40.4) | 4 (15.4) |
| Respiratory disease, n (%) | 26 (45.6) | 1 (3.8) |
| of which asthma, n (%) | 9 (15.8) | 1 (3.8) |
| of which COPD, n (%) | 14 (24.6) | 0 (0.0) |
| Diabetes, n (%) | 7 (12.3) | 1 (3.8) |
| Chronic kidney disease, n (%) | 4 (7.0) | 4 (15.4) |
| (Prior) malignancy, n (%) | 5 (8.8) | 0 (0.0) |
| Identified pathogen, n (%) 1 | ||
| Gram-positive bacteria | 10 (17.5) | |
| Gram-negative bacteria | 7 (12.3) | |
| Virus | 4 (7.0) | |
| Unknown pathogen | 38 (66.7) | |
| Disease severity on admission (median [IQR]) | ||
| qSOFA score | 1 [0, 1] | |
| MEWS score | 3 [2, 4] | |
| CURB-65 score | 1 [1, 2] | |
| Routine laboratory values (median [IQR]) | ||
| Leukocyte count (x109/L) | 15.8 [10.7, 19.1] | |
| Neutrophil count (x109/L) | 13.0 [8.2, 16.1] | |
| Lymphocyte count (x109/L) | 0.8 [0.6, 1.2] | |
| Platelet count (x109/L) | 295 [219, 359] | |
| C-Reactive Protein (mg/L) | 158 [73, 276] | |
| Creatinine (µmol/L) | 86 [72, 117] | |
| Urea (mg/dl) | 6.8 [5.1, 9.5] | |
| Clinical course | ||
| Need for supplementary oxygen, n (%) | 48 (84.2) | |
| Length of hospital stay, days (median [IQR]) | 4 [2, 7] | |
| Time to clinical stability, days (median [IQR]) 2 | 3 [2, 5] | |
| Time to clinical stability, ≤3 days, n (%) | 36 (63.2) | |
| 30-day mortality, n (%) | 1 (1.8) | |
COPD, chronic obstructive pulmonary disease; qSOFA quick sequential organ failure assessment; MEWS modified early warning score; CURB-65; confusion, blood urea nitrogen, respiratory rate, blood pressure, and age >65.
1 Pathogen were identified using various methods: culture (blood, sputum and pleural fluid), nasal or throat swab PCR, or urine antigen tests specific for Legionella or Streptococcus pneumoniae. Included are only those organisms cultured or identified within the first 24 hours of ward admission and subsequently confirmed as causative agents by the treating physician. Numbers do not add up to 100% as some patients suffered from multiple causative pathogens. Identified pathogens were as follows: Streptococcus pneumoniae (n=6), Influenza A virus (n=3), Haemophilus influenzae (n=3), Moraxella catarrhalis (n=2), Pseudomonas aeruginosa (n=1), Pseudomonas fluorescens (n=1), Legionella species (n=1), Respiratory Syncytial Virus (n=1), Staphylococcus aureus (n=1), Serratia marcescens (n=1), Lactobaccilus casei (n=1, from pleural fluid puncture), Streptococcus intermedius (n=1), Streptococcus milleri (n=1), Actinomyces neuii (n=1).
2 Defined as the Halm’s criteria: temperature ≤37.2°C, heart rate ≤100 bpm, systolic blood pressure ≥90 mmHg, respiratory rate ≤24 bpm, and oxygen saturation ≥90% for the entire day (26).