Table I.
Baseline characteristics of the patients (mean ± SD, n = 1230)
| Variable | M. pneumoniae pneumonia group | Other pneumonias group | t or χ2 value | Value of p |
|---|---|---|---|---|
| Age [years] | 31.3 ±11.6 | 50.4 ±22.4 | 15.702 | < 0.001 |
| Age ≥ 65 years [%] | 2.2 | 31.8 | 132.151 | < 0.001 |
| Male sex [%] | 39.8 | 51.0 | 13.717 | < 0.001 |
| Confusion [%] | 0 | 2.1 | 7.963 | 0.005 |
| Body temperature [°C] | 37.5 ±1.1 | 37.5 ±1.1 | 0.281 | 0.779 |
| Respiratory rate [breaths/min] | 19.7 ±2.3 | 20.6 ±2.9 | 5.053 | < 0.001 |
| Low blood pressure* [%] | 15.1 | 14.2 | 0.171 | 0.679 |
| WBC count [109/l] | 7.46 ±3.65 | 8.83 ±4.42 | 5.353 | < 0.001 |
| PaO2/FiO2 ≤ 250 mm Hg [%] | 0 | 3.6 | 13.914 | < 0.001 |
| Serum BUN ≥ 7 mmol/l [%] | 0 | 7.5 | 29.413 | < 0.001 |
| Platelet count [109/l] | 245.69 ±96.52 | 226.57 ±89.34 | 3.469 | 0.001 |
| CURB-65 score: 0-1-2-3-4 [%] | 82.8-17.2-0-0-0 | 53.8-35.4-9.4-1.1-0.2 | 107.118 | < 0.001 |
| Multilobar opacities, n (%) | 15.1 (56) | 29.3 (251) | 29.295 | < 0.001 |
| Consolidation, n (%) | 7.5 (28) | 12.1 (104) | 5.838 | 0.016 |
*
Systolic < 90 mm Hg; or diastolic ≤ 60 mm Hg, WBC – white blood cell, PaO2/FiO2 – arterial oxygen pressure/fraction inspired oxygen, BUN – blood urea nitrogen, CURB-65 – confusion, urea, respiratory rate, blood pressure, and age