Table 1.
Demographic and clinical characteristics of patients with lower respiratory tract infection
| Variable | Intervention group (n = 398) | Control group (n = 402) |
|---|---|---|
| Age, years | 60.8 ± 18.2 | 60.9 ± 17.7 |
| Male (%) | 232 (58.3) | 224 (55.7) |
| Observation | ||
| Body mass index (kg/cm2) | 23.3 ± 3.8 | 23.5 ± 5.2 |
| Temperature (°C) | 37.0 (36.5–37.7) | 36.8 (36.5–37.5) |
| Respiratory frequency (breaths/min) | 20.0 (20.0–22.0) | 20.0 (20.0–22.0) |
| Heart rate (beats/min) | 90.0 (80.0–100.0) | 90.0 (80.0–100.0) |
| Systolic blood pressure (mmHg) | 125.5 (116.0–140.0) | 128.0 (117.0–142.0) |
| Final diagnosis (%) | ||
| CAP | 242 (60.8) | 214 (53.2) |
| CURB-65 score a | ||
| 0–1 | 213/240 (88.8) | 180/214 (84.5) |
| 2 | 22/240 (9.2) | 29/214 (13.6) |
| 3–5 | 5/240 (2.1) | 4/214 (1.9) |
| AECOPD | 98 (24.6) | 108 (26.9) |
| AE of bronchiectasis | 45 (11.3) | 56 (13.9) |
| Onset of illness to admission (days) | 7.0 (5.0–14.0) | 7.0 (5.0–14.0) |
| Symptoms (%) | ||
| Fever | 266 (66.8) | 254 (63.2) |
| Cough | 383 (96.2) | 393 (97.8) |
| Chest pain | 103 (25.9) | 122 (30.3) |
| Dyspnoea | 306 (76.9) | 309 (76.9) |
| Catarrhal symptoms | 89 (22.4) | 97 (24.1) |
| Headache | 79 (19.8) | 66 (16.4) |
| Diarrhoea | 53 (13.3) | 47 (11.7) |
| Co-morbidity (%) | ||
| Chronic respiratory disease | 168 (42.2) | 180 (44.8) |
| Cardiovascular disease | 176 (44.2) | 182 (45.3) |
| Diabetes | 80 (20.1) | 101 (25.1) |
| Renal disease | 14 (3.5) | 18 (4.5) |
| Liver disease | 8 (2.0) | 4 (1.0) |
| Cancer | 14 (3.5) | 17 (4.2) |
| Current smoker | 73 (18.3) | 83 (20.6) |
| Influenza vaccine (<1 year) | 53 (13.3) | 51 (12.7) |
| Antibiotics use before admission | 6 (1.5) | 7 (1.7) |
| Laboratory test | ||
| Procalcitonin (ng/mL) b | ||
| <0.1 | 19/280 (6.8) | 20/262 (7.6) |
| 0.1–0.24 | 124/280 (44.3) | 120/262 (45.8) |
| ≥0.25 | 137/280 (48.9) | 122/262 (46.6) |
| White blood cell count (×109/L) | 6.6 (5.3–9.4) | 7.0 (5.3–9.3) |
| Neutrophil count (×109/L) | 4.6 (3.1–7.0) | 4.5 (3.1, 6.9) |
| Lymphocyte count (×109/L) | 1.3 (1.0–1.9) | 1.5 (1.0–1.9) |
| Haemoglobin (g/L) | 130.0 (120.0–141.0) | 128.0 (118.0–140.0) |
| Platelet count (G/L) | 222.5 (177.0–277.0) | 237.0 (185.0–292.0) |
| Albumin (g/L) | 38.7 ± 4.4 | 38.7 ± 4.5 |
| Aspartate aminotransferase (U/L) | 20.0 (16.0–30.0) | 19.0 (15.0–24.0) |
| Lactate dehydrogenase (U/L) | 186.0 (162.0–230.0) | 187.0 (157.0–221.0) |
| Alkaline phosphatase (U/L) | 66.0 (56.0–86.0) | 68.0 (58.0–86.0) |
| Total bilirubin (μmol/L) | 9.7 (6.9–13.3) | 9.6 (6.6–13.1) |
| Direct bilirubin (μmol/L) | 3.3 (2.4–4.2) | 3.1 (2.5–4.2) |
| Blood glucose (mmol/L) | 5.5 (4.9–6.5) | 5.5 (5.0–6.7) |
| Creatinine (μmol/L) | 64.5 (55.4–78.2) | 64.1 (53.4–76.6) |
| Blood urea nitrogen (mmol/L) | 4.4 (3.4–5.7) | 4.5 (3.6–5.9) |
| Oxygenation index (mmHg) | 338.0 (290.0–381.0) | 343.0 (300.0–388.0) |
AE, acute exacerbation; AECOPD, acute exacerbation of chronic obstructive pulmonary disease; CAP, community-acquired pneumonia; CURB-65, a pneumonia severity score calculator (measured by 5 risk factors in total, with 1 point for each criterion satisfied: confusion defined as an abbreviated mental test score ≤8; blood urea nitrogen ≥ 7mmol/l; respiratory rate ≥30 bpm; systolic blood pressure < 90 mmHg or diastolic blood pressure ≤60 mmHg; age ≥65 years).
Data are presented as mean ± SD (standard deviation) or as median (interquartile range) for continuous variables and as percent for categorical variables. Categorical variables were compared using χ2 tests, and continuous variables were compared using Wilcoxon rank-sum test or Student's t-test.
The denominator is the number of community-acquired pneumonia.
The denominator is the number of study participants that received the procalcitonin test.