Table 1.
Patient characteristics and outcomes
| CAP (full cohort) | CAP (propensity score matching) | |||||
|---|---|---|---|---|---|---|
| Variable | (N = 5640) | (N = 156) | ||||
| Case (n = 89) | Control (n = 5551) | p value | Case (n = 78) | Control (n = 78) | p value | |
| Age, mean (SD), years | 64 (17) | 70 (17) | 0.001 | 64 (17) | 65 (19) | 0.673 |
| Male sex, n (%) | 52 (58) | 3,456 (62) | 0.460 | 48 (62) | 50 (64) | 0.740 |
| Current smoker, n (%) | 18 (31) | 1,223 (22) | 0.129 | 18 (31) | 20 (26) | 0.518 |
| Current alcohol use, n (%) | 4 (7) | 787 (14) | 0.097 | 4 (7) | 10 (13) | 0.240 |
| Previous antibiotic, n (%) | 16 (19) | 1,222 (23) | 0.391 | 15 (20) | 17 (23) | 0.690 |
| Influenza vaccine, n (%) | 23 (29) | 1,833 (45) | 0.004 | 20 (29) | 19 (35) | 0.543 |
| Pneumococcal vaccine, n (%) | 26 (32) | 822 (20) | 0.010 | 24 (34) | 10 (18) | 0.045 |
| Previous inhaled corticosteroids, n (%) | 9 (10) | 1,053 (19) | 0.034 | 7 (9) | 15 (19) | 0.065 |
| Previous systemic corticosteroids, n (%) | 3 (3) | 217 (5) | 0.525 | 3 (4) | 4 (6) | 0.701 |
| Previous episode of pneumonia, n (%) | 16 (18) | 745 (14) | 0.291 | 15 (19) | 9 (12) | 0.232 |
| Comorbidities, n (%) a | 55 (62) | 4,074 (74) | 0.013 | 48 (62) | 55 (71) | 0.237 |
| Chronic respiratory disease | 32 (36) | 2,472 (45) | 0.080 | 29 (37) | 32 (41) | 0.623 |
| Chronic cardiovascular disease | 10 (11) | 918 (17) | 0.176 | 9 (12) | 14 (18) | 0.259 |
| Diabetes mellitus | 16 (18) | 1,178 (21) | 0.433 | 13 (17) | 13 (17) | > 0.999 |
| Neurologic disease | 10 (11) | 1,007 (19) | 0.079 | 9 (12) | 13 (17) | 0.357 |
| Chronic renal disease | 13 (15) | 473 (9) | 0.044 | 11 (14) | 14 (18) | 0.513 |
| Chronic liver disease | 5 (6) | 272 (5) | 0.627 | 5 (6) | 3 (4) | 0.719 |
| Previous neoplasm | 16 (18) | 512 (10) | 0.008 | 14 (18) | 15 (19) | 0.837 |
| Nursing home, n (%) | 2 (3) | 364 (7) | 0.434 | 2 (3) | 4 (5) | 0.696 |
| Cough, n (%) | 68 (77) | 4,270 (78) | 0.882 | 58 (75) | 60 (7) | 0.815 |
| Purulent sputum, n (%) | 40 (45) | 3,097 (57) | 0.024 | 32 (42) | 51 (68) | 0.001 |
| Dyspnea, n (%) | 62 (70) | 3,907 (72) | 0.818 | 54 (70) | 59 (78) | 0.291 |
| Pleuritic pain, n (%) | 23 (26) | 1,889 (35) | 0.109 | 18 (24) | 34 (44) | 0.009 |
| Fever, n (%) | 56 (63) | 4,157 (76) | 0.006 | 46 (59) | 48 (62) | 0.744 |
| Confusion, n (%) | 12 (13) | 1,147 (21) | 0.090 | 11 (14) | 10 (13) | 0.815 |
| C-reactive protein at baseline, median (IQR), mg/dL | 25.3 (13.9; 39.4) | 17.8 (8.5; 27.3) | < 0.001 | 22.6 (10.3; 31.6) | 25.1 (16.4; 33.9) | 0.244 |
| C-reactive protein at days 2 and 3, median (IQR), mg/dL | 25.3 (15.5; 31) | 15.3 (7.4; 24.1) | < 0.001 | 24.5 (15.5; 30.6) | 20.6 (8.5; 28) | 0.269 |
| Neutrophils at baseline, median (IQR), cell/mm3 | 9,810 (4,686; 15,032) | 10,160 (6,622; 14,661) | 0.380 | 9,626 (5,376; 14,711) | 10,640 (7,304; 14,280) | 0.388 |
| Neutrophils at days 2 and 3, median (IQR), cell/mm3 | 11,550 (7,650; 17,606) | 8,306 (5,465; 12,466) | 0.009 | 11,659 (7,769; 17,606) | 8,835 (5,192; 12,220) | 0.081 |
| Lymphocytes at baseline, median (IQR), cell/mm3 | 660 (380; 1192) | 900 (543; 1,386) | 0.001 | 661 (386; 1,152) | 900 (428; 1,463) | 0.135 |
| Lymphocytes at days 2 and 3, median (IQR), cell/mm3 | 600 (387; 816) | 902 (531; 1,379) | 0.003 | 592 (387; 753) | 722 (520; 1,122) | 0.057 |
| PaO2/FiO2, median (IQR) | 238 (173; 295) | 276 (233; 316) | < 0.001 | 241 (177; 300) | 248 (184; 310) | 0.656 |
| PSI score, median (IQR) | 104 (76; 135) | 101 (78; 126) | 0.664 | 105.5 (70; 137.5) | 114.5 (83; 134) | 0.568 |
| PSI risk class IV–V, n (%) b | 58 (66) | 2,366 (62) | 0.411 | 53 (69) | 34 (68) | 0.922 |
| SOFA score, median (IQR) | 3 (2; 4) | 2 (1; 3) | 0.087 | 3 (2; 4) | 3 (2; 5) | 0.685 |
| Severe CAP, n (%) | 46 (69) | 1,337 (32) | < 0.001 | 43 (67) | 35 (56) | 0.215 |
| Major criteria | 11 (16) | 254 (6) | 0.002 | 11 (17) | 8 (13) | 0.502 |
| ≥ 3 minor criteria | 18 (27) | 752 (18) | 0.053 | 16 (25) | 12 (19) | 0.446 |
| Major and ≥ 3 minor criteria | 17 (25) | 331 (8) | < 0.001 | 16 (25) | 15 (24) | 0.916 |
| Bacteremia, n (%) c | 22 (29) | 554 (13) | < 0.001 | 20 (26) | 25 (32) | 0.377 |
| Pleural effusion, n (%) | 13 (22) | 837 (15) | 0.156 | 13 (22) | 15 (20) | 0.706 |
| Multilobar involvement, n (%) | 51 (57) | 1,485 (27) | < 0.001 | 44 (56) | 44 (56) | > 0.999 |
| ARDS, n (%) | 21 (26) | 271 (5) | < 0.001 | 18 (25) | 14 (19) | 0.423 |
| Acute renal failure, n (%) | 31 (44) | 1,510 (28) | 0.002 | 28 (42) | 34 (44) | 0.888 |
| Septic shock, n (%) | 10 (11) | 396 (7) | 0.150 | 10 (13) | 9 (12) | 0.807 |
| Length of hospital stay, median (IQR), days | 12 (9; 24) | 7 (5; 11) | < 0.001 | 13 (9; 25) | 10 (6.5; 15.5) | 0.007 |
| ICU admission, n (%) | 56 (63) | 1,040 (19) | < 0.001 | 54 (69) | 46 (59) | 0.182 |
| ICU mortality, n (%) d | 5 (9) | 116 (11) | 0.605 | 5 (9) | 10 (22) | 0.082 |
| Length of ICU stay, median (IQR), days d | 15.5 (10.5; 29.5) | 12 (8; 20) | 0.005 | 15.5 (10; 30) | 12 (8; 23) | 0.074 |
| Mechanical ventilation, n (%) e | < 0.001 | 0.198 | ||||
| Non-invasive | 3 (5) | 183 (4) | 0.491 | 5 (6) | 12 (15) | 0.040 |
| Invasive | 24 (40) | 360 (7) | < 0.001 | 27 (35) | 24 (31) | 0.308 |
| In-hospital mortality, n (%) | 11 (12) | 432 (8) | 0.112 | 10 (13) | 16 (21) | 0.197 |
| 3-day mortality, n (%) | 1 (1) | 82 (1) | > 0.999 | 1 (1) | 4 (5) | 0.367 |
| 30-day mortality, n (%) | 10 (13) | 439 (8) | 0.113 | 9 (12) | 15 (19) | 0.183 |
| 1-year mortality, n (%) | 13 (23) | 600 (11) | 0.004 | 12 (18) | 16 (21) | 0.664 |
ARDS, acute respiratory distress syndrome; CAP, community-acquired pneumonia; IQR, interquartile range; ICU, intensive care unit; PSI, Pneumonia Severity Index; SD, standard deviation. Percentages calculated with non-missing data only. aPossibly > 1 comorbidity. bStratified by 30-day mortality risk for CAP: classes I–III (≤ 90 points) had low mortality risk, while classes IV–V (> 90 points) had the highest mortality risk. cCalculated only for patients with blood samples. dCalculated only for patients admitted to intensive care. ePatients who initially received non-invasive ventilation yet subsequently needed intubation were included in the invasive mechanical ventilation group
Bold numbers refers to statistically significant differences