| Variable | Total population | Cases with microbial sampling | Cases with a pathogen determined | ||||||
| CAP <65 yrs | CAP ≥65 yrs | p-value | CAP <65 yrs | CAP 65 ≥yrs | p-value | CAP <65 yrs | CAP ≥65 yrs | p-value | |
| Streptococcus pneumoniae | 375 (9.2) | 330 (8.9) | 0.063 | 375/3947 (9.5) | 330/3444 (9.6) | 0.906 | 375 (28.0) | 330 (33.2) | 0.007 |
| Mycoplasma pneumoniae | 345 (8.4) | 45 (1.2) | 0.001 | 345/3560 (9.7) | 45/2972 (1.5) | <0.001 | 345 (25.1) | 45 (4.5) | <0.001 |
| Legionella spp. | 177 (4.3) | 142 (3.8) | 0.249 | 177/3777 (4.7) | 142/3204 (4.4) | 0.612 | 177 (13.2) | 142 (14.3) | 0.463 |
| Haemophilus influenzae | 86 (2.1) | 53 (1.4) | 0.023 | 86/3881 (2.2) | 53/3344 (1.6) | 0.052 | 86 (6.4) | 53 (5.3) | 0.269 |
| Enterobacteria | 52 (1.3) | 98 (2.6) | 0.001 | 52/3881 (1.3) | 98/3344 (2.9) | <0.001 | 52 (3.9) | 98 (9.9) | <0.001 |
| Pseudomonas aeruginosa | 16 (0.4) | 28 (0.8) | 0.034 | 16/3881 (0.4) | 28/3344 (0.8) | 0.021 | 16 (1.2) | 28 (2.8) | 0.004 |
| Staphylococcus aureus | 51 (1.2) | 38 (1.0) | 0.344 | 51/3881 (1.3) | 38/3344 (1.1) | 0.495 | 51 (3.8) | 38 (3.8) | 0.989 |
| Moraxella catarrhalis | 9 (0.2) | 12 (0.3) | 0.384 | 9/3881 (0.2) | 12/3344 (0.4) | 0.318 | 9 (0.7) | 12 (1.2) | 0.177 |
| Chlamydophila pneumoniae | 5 (0.1) | 0 (0.0) | 0.033 | 5/3759 (0.1) | 0/3198 (0.0) | 0.039 | 5 (0.4) | 0 (0.0) | 0.054 |
| Influenza A | 61 (1.5) | 78 (2.1) | 0.044 | 61/3158 (1.9) | 78/2565 (3.0) | 0.007 | 64 (4.6) | 78 (7.8) | 0.001 |
Data are presented as n (%) and n/N (%), unless otherwise stated. The aetiology is given according to three different denominators: 1) total population: number of pathogens per total population; 2) cases with microbial sampling: number of pathogens per patients having received at least one microbial investigation able to detect the pathogen in question; and 3) cases with a pathogen determined: number of pathogens per population with a pathogen established.