Table 2 Pneumonia aetiology, based on ICD-9_CM codes
From: Pneumonia burden in elderly patients: a classification algorithm using administrative data
| Aetiology | HCAP | PNP | CAP |
|---|---|---|---|
| n = 2257 | n = 6775 | n = 17107 | |
| n% | n% | n% | |
| Bronchopneumonia, organism unspecified | 903(40.0) | 3482(51.4) | 8148(47.6) |
| Pneumonia, organism unspecified | 637(28.2) | 1830(27.0) | 4901(28.6) |
| Pneumonia, specified organisms | |||
| Bacterial pneumonia, unspecified | 330(14.6) | 863(12.7) | 2299(13.4) |
| Pneumonia due to Pseudomonas | 82(3.6) | 44(0.6) | 200(1.2) |
| Pneumonia due to other specified bacteria | 59(2.6) | 105(1.6) | 247(1.4) |
| Pneumococcal pneumonia [Streptococcus pneumoniae] | 45(2.0) | 108(1.6) | 289(1.7) |
| Methicillin-susceptible pneumonia due to Staphylococcus aureus | 32(1.4) | 16(0.2) | 99(0.6) |
| Pneumonia due to Klebsiella pneumoniae | 17(0.7) | 26(0.4) | 93(0.5) |
| Pneumonia due to other gram-negative bacteria | 15(0.7) | 10(0.1) | 80(0.5) |
| Pneumonia due to Staphylococcus, unspecified | 15(0.7) | 19(0.3) | 122(0.7) |
| Pneumonia due to Escherichia coli [E. coli] | 13(0.6) | 9(0.1) | 54(0.3) |
| Respiratory conditions due to chemical fumes and vapours | 14(0.6) | 89(1.3) | 23(0.1) |
| Other | 95(4.3) | 174(2.6) | 552(3.2) |