Table 1. Patients’ characteristics by study period.
| Variable | 1997–2001 (n = 285) |
2002–2006 (n = 340) |
2007–2011 (n = 291) |
2012–2016 (n = 204) |
P-value for trend |
|---|---|---|---|---|---|
| Age, mean (SD), years | 67.4 (16.4) | 66.9 (18.0) | 65.9 (18.2) | 67.6 (18.4) | 0.82 |
| Age ≥65 years, n (%) | 194 (68) | 215 (63) | 168 (58) | 124 (61) | 0.029 |
| Male sex, n (%) | 205 (72) | 186 (55) | 173 (60) | 130 (64) | 0.095 |
| Current smoker, n (%) | 99 (35) | 96 (28) | 80 (28) | 47 (23) | 0.006 |
| Current alcohol consumer, n (%) | 72 (26) | 60 (18) | 47 (17) | 30 (15) | 0.002 |
| Previous antibiotic, n (%) | 31 (11) | 61 (18) | 41 (16) | 32 (16) | 0.18 |
| Influenza vaccine, n (%) | 20 (32) | 127 (42) | 118 (47) | 49 (25) | 0.030 |
| Pneumococcal vaccine, n (%) | 11 (18) | 45 (15) | 40 (16) | 36 (19) | 0.51 |
| Previous inhaled corticosteroids, n (%) | 57 (20) | 67 (20) | 77 (27) | 33 (17) | 0.87 |
| Previous systemic corticosteroids, n (%) | 12 (12) | 27 (8) | 9 (3) | 10 (5) | 0.004 |
| Previous episode of pneumonia (last year), n (%) | 28 (11) | 71 (21) | 26 (10) | 14 (7) | 0.012 |
| Comorbidities, n (%)a | 221 (78) | 240 (71) | 187 (64) | 131 (64) | <0.001 |
| Chronic respiratory disease | 172 (61) | 160 (47) | 127 (45) | 65 (33) | <0.001 |
| COPD | 138 (49) | 98 (29) | 74 (26) | 39 (20) | <0.001 |
| Asthma | 9 (3) | 24 (7) | 16 (6) | 7 (4) | 0.88 |
| Bronchiectasis | 9 (3) | 7 (2) | 11 (4) | 1 (1) | 0.28 |
| Otherb | 16 (6) | 31 (9) | 26 (9) | 18 (9) | 0.15 |
| Chronic cardiovascular disease | 47 (17) | 52 (15) | 41 (14) | 11 (6) | 0.001 |
| Diabetes mellitus | 55 (19) | 78 (23) | 41 (14) | 40 (20) | 0.46 |
| Neurological disease | 32 (11) | 42 (13) | 46 (17) | 35 (18) | 0.016 |
| Chronic renal disease | 23 (8) | 17 (5) | 21 (7) | 17 (9) | 0.64 |
| Chronic liver disease | 30 (11) | 23 (7) | 15 (5) | 16 (8) | 0.15 |
| Nursing-home, n (%) | 9 (3) | 16 (5) | 24 (8) | 10 (5) | 0.093 |
| Creatinine, mg/dL, median (IQR) | 1.1 (0.9; 1.4) | 1.2 (1; 1.6) | 1 (0.8; 1.5) | 1.2 (0.9; 1.7) | 0.47 |
| C-reactive protein, mg/dL, median (IQR) | 169 (85; 296) | 221 (111; 317) | 242 (147; 308) | 246 (148; 290) | 0.59 |
| PaO2/FiO2, median (IQR) | 276 (229; 314) | 281 (243; 319) | 267 (218; 301) | 266 (203; 308) | 0.002 |
| SOFA score, median (IQR) | 2 (2; 4) | 3 (2; 4) | 2 (1; 3) | 2 (1; 3) | <0.001 |
| SOFA score ≥5, n (%)c | 53 (19) | 54 (16) | 35 (12) | 12 (8) | 0.002 |
| PSI score, median (IQR) | 102 (80; 127) | 100 (77; 126) | 100 (75; 120) | 105 (80; 125) | 0.43 |
| PSI risk class IV–V, n (%)d | 173 (62) | 188 (60) | 107 (55) | 59 (64) | 0.57 |
| CURB-65 risk class 3–5, n (%)e | 74 (26) | 88 (26) | 51 (20) | 31 (21) | 0.090 |
| Pneumococcal bacteremia, n (%) | 104 (39) | 113 (41) | 93 (37) | 70 (41) | 0.90 |
| Invasive pneumococcal pneumonia, n (%) | 111 (41) | 121 (42) | 101 (39) | 73 (42) | 0.98 |
| Pleural effusion, n (%) | 49 (17) | 59 (17) | 68 (24) | 30 (16) | 0.64 |
| Multilobar, n (%) | 75 (26) | 97 (29) | 76 (26) | 66 (32) | 0.28 |
| ARDS, n (%) | 12 (4) | 13 (4) | 19 (7) | 16 (8) | 0.026 |
| Acute renal failure, n (%) | 80 (28) | 115 (34) | 83 (29) | 72 (36) | 0.21 |
| Septic shock, n (%) | 27 (9) | 34 (10) | 50 (17) | 31 (15) | 0.005 |
| Empiric antibiotic therapy, n (%) | |||||
| Monotherapy | 50 (18) | 81 (24) | 60 (21) | 33 (16) | 0.63 |
| Fluoroquinolones | 8 (3) | 68 (20) | 50 (17) | 19 (9) | 0.025 |
| β-lactams | 34 (12) | 11 (3) | 10 (3) | 12 (6) | 0.003 |
| Other therapy | 8 (3) | 2 (1) | 0 (0) | 2 (1) | 0.020 |
| Combination therapies | 232 (82) | 259 (76) | 230 (79) | 169 (84) | 0.63 |
| β-lactams plus macrolides | 185 (66) | 148 (44) | 87 (30) | 97 (48) | <0.001 |
| β-lactams plus fluoroquinolones | 4 (1) | 84 (25) | 119 (41) | 57 (28) | <0.001 |
| Other combination therapies | 43 (15) | 27 (8) | 24 (8) | 15 (7) | 0.005 |
| Appropriate empiric treatment, n (%) | 274 (97) | 328 (97) | 280 (97) | 198 (99) | 0.63 |
Abbreviations: ARDS indicates acute respiratory distress syndrome; COPD = chronic obstructive pulmonary disease; CURB-65 = Consciousness, Urea, Respiratory rate, Blood pressure, 65 years old; IQR, interquartile range; PSI, pneumonia severity index; PaO2/FiO2 = arterial oxygen tension to inspired oxygen fraction ratio; SD, standard deviation; SOFA, sequential organ failure assessment. Percentages calculated on non-missing data.
a May have >1 comorbid condition.
b Other respiratory diseases include sequelae of pulmonary tuberculosis, pulmonary hypertension, and interstitial lung disease.
c Optimal cut-off value to predict 30-day mortality using ROC curves.
d Stratified according to 30-day risk mortality for community-acquired pneumonia: risk classes I–III (≤90 points) have low mortality and risk classes IV–V (>90 points) have the highest mortality.
e Stratified according to 30-day risk mortality for community-acquired pneumonia: risk classes 0–2 have low mortality and risk classes 3–5 have the highest mortality.