Table 2.
Microbial aetiology
| CAP (full cohort) | CAP (propensity score matching) | |||||
|---|---|---|---|---|---|---|
| Variable | (N = 5,640) | (N = 156) | ||||
| Case (n = 89) | Control (n = 5,551) | p value | Case (n = 78) | Control (n = 78) | p value | |
| Patients with defined aetiology | 62 (70) | 2,302 (41) | < 0.001 | 57 (73) | 59 (76) | 0.714 |
| Streptococcus pneumoniae | 22 (35) | 982 (43) | 0.259 | 19 (33) | 25 (42) | 0.316 |
| Respiratory virus | 13 (21) | 335 (15) | 0.159 | 13 (23) | 6 (10) | 0.066 |
| Polymicrobial | 21 (34) | 320 (14) | < 0.001 | 19 (33) | 20 (34) | 0.949 |
| Atypical | 0 (0) | 119 (5) | 0.073 | 0 (0) | 2 (3) | 0.496 |
| Mycoplasma pneumoniae | 0 (0) | 54 (2) | 0.401 | 0 (0) | 1 (2) | > 0.999 |
| Coxiella burnetii | 0 (0) | 22 (1) | > 0.999 | 0 (0) | 1 (2) | > 0.999 |
| Chlamydophila pneumoniae | 0 (0) | 41 (2) | 0.626 | 0 (0) | 0 (0) | - |
| Chlamydophila psittaci | 0 (0) | 2 (0.1) | > 0.999 | 0 (0) | 0 (0) | - |
| Legionella pneumophila | 0 (0) | 151 (7) | 0.031 | 0 (0) | 0 (0) | - |
| Staphylococcus aureus | 5 (8) | 61 (3) | 0.028 | 5 (9) | 0 (0) | 0.026 |
| Haemophilus influenzae | 0 (0) | 97 (4) | 0.180 | 0 (0) | 1 (2) | > 0.999 |
| Pseudomonas aeruginosa | 1 (2) | 87 (4) | 0.728 | 1 (2) | 2 (3) | > 0.999 |
| Gram-negative Enterobacteriaceae | 0 (0) | 51 (2) | 0.643 | 0 (0) | 1 (2) | > 0.999 |
| Moraxella catarrhalis | 0 (0) | 6 (0.3) | > 0.999 | 0 (0) | 0 (0) | - |
| Other Streptococcus species | 0 (0) | 6 (0.3) | > 0.999 | 0 (0) | 0 (0) | - |
| Others | 0 (0) | 82 (4) | 0.275 | 0 (0) | 2 (3) | 0.496 |
CAP, community-acquired pneumonia. Results are given as n (%). Percentages calculated on non-missing data. Pathogen percentages are related to the number of patients with an aetiologic diagnosis in each group