Aetiological definition used for diagnosis of pneumonia in patients by chronic obstructive pulmonary disease(COPD) diagnosis
| Non-COPD | COPD | |
| Subjects n | 529 | 215 |
| Streptococcus pneumoniae | 42 (7.3) | 14 (6.5) |
| Staphylococcus aureus | 32 (6.0) | 7 (3.2) |
| Pseudomonas aeruginosa# | 7 (1.3) | 12 (5.6)ƒ |
| Haemophilus influenzae | 10 (1.9) | 8 (3.7)## |
| Enterobacteriaceae¶ | 13 (2.5) | 4 (1.9) |
| Miscellaneous+ | 5 (0.9) | 2 (0.9) |
| Other Gram-positive cocci§ | 4 (0.7) | 0 (0) |
| Polymicrobial | 6 (1.1) | 6 (2.8) |
| All identified pathogens | 119 (22.5) | 53 (24.6) |
| Test performed | 469 (88.6) | 182 (84.6) |
| No test performed | 60 (11.3) | 33 (15.3) |
Data are presented as n (%) unless otherwise stated. Statistical comparisons were not performed for Enterobacteriaceae, miscellaneous or other Gram-positive cocci due to the small sample size. #: all isolates occurred in non-bronchiectatic patients; ¶: including Escherichia coli, Klebsiella pneumoniae, K. oxytoca and Proteus mirabilis, +: comprising Acinetobacter spp., Aspergillus spp. and H. parainfluenzae; §: including Enterococcus spp. and Streptococcus spp. ƒ: p = 0.001; ##: p = 0.07.