| Variables | With ATS/IDSA criteria | With PSI | ||
| OR (95% CI) | p-value | OR (95% CI) | p-value | |
| Serotypes | ||||
| H | 1 | 1 | ||
| O | 1.72 (0.40–7.41) | 0.46 | 1.28 (0.29–5.60) | 0.73 |
| L | 7.02 (1.72–28.61) | <0.01 | 5.28 (1.29–21.58) | <0.05 |
| ATS/IDSA criteria | 4.80 (1.89–12.13) | <0.01 | ||
| PSI class V | 9.50 (3.06–29.46) | <0.001 | ||
| Alcohol abuse | 3.99 (1.39–11.39) | 0.01 | 3.16 (1.18–8.46) | <0.05 |
| Charlson score | 1.30 (1.08–1.57) | <0.01 | 1.22 (1.01–1.46) | <0.05 |
| Age | 1.02 (0.99–1.05) | 0.11 | ||
H serotypes: 1, 5 and 7 F. L serotypes: 3, 6A, 6B, 8, 19F and 23F. O serotypes; non-L, non-H serotypes. ATS: American Thoracic Society; IDSA: Infectious Diseases Society of Americal; PSI: Pneumonia Severity Index.