Table 4. Risk factors relevant to severe exacerbations of COPD (emergency visits, hospitalization and ICU stay).
| Clinical characteristics | Emergency visits | Hospitalization | ICU stay | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| No (n=817) | ≥1 (n=284) | P | No (n=586) | ≥1 (n=515) | P | No (n=1,039) | ≥1 (n=62) | P | |||
| Age (year) | 65.2±11.1 | 69.6±11.5 | <0.001 | 63.4±11.2 | 69.6±10.5 | <0.001 | 66.0±11.3 | 72.5±9.2 | <0.001 | ||
| Male | 534 (65.4) | 192 (67.6) | 0.492 | 374 (63.8) | 352 (68.3) | 0.114 | 687 (66.1) | 39 (62.9) | 0.603 | ||
| Height (cm) | 165.1±8.4 | 165.4±7.9 | 0.631 | 164.9±8.3 | 165.6±8.1 | 0.145 | 165.2±8.3 | 165.9±8.0 | 0.517 | ||
| Weight (kg) | 62.1±12.1 | 60.2±12.2 | 0.023 | 62.5±12.1 | 60.5±12.1 | 0.007 | 61.7±12.2 | 60.0±12.1 | 0.255 | ||
| BMI (kg/m2) | 22.7±3.8 | 21.9±4.4 | 0.004 | 22.9±3.8 | 22.0±4.1 | <0.001 | 22.5±4.0 | 21.8±4.3 | 0.150 | ||
| Smoking status | 0.209 | <0.001 | 0.810 | ||||||||
| Current- | 193 (23.6) | 57 (20.1) | 167 (28.5) | 83 (16.1) | 238 (22.9) | 12 (19.4) | |||||
| Ex- | 366 (44.8) | 144 (50.7) | 233 (39.8) | 277 (53.8) | 480 (46.2) | 30 (48.4) | |||||
| Never- | 258 (31.6) | 83 (29.2) | 186 (31.7) | 155 (30.1) | 321 (30.9) | 20 (32.3) | |||||
| Smoking index (pack·year) | 22.9±25.7 | 22.9±23.8 | 0.966 | 22.0±24.1 | 23.9±26.4 | 0.217 | 22.6±24.7 | 26.9±33.3 | 0.329 | ||
| CB | 641 (78.5) | 249 (87.7) | 0.001 | 434 (74.1) | 456 (88.5) | <0.001 | 832 (80.1) | 59 (93.5) | 0.009 | ||
| mMRC dyspnea score | < 0.001 | <0.001 | <0.001 | ||||||||
| 0 | 86 (10.5) | 12 (4.2) | 72 (12.3) | 26 (5.0) | 97 (9.3) | 1 (1.6) | |||||
| 1 | 319 (39.0) | 63 (22.2) | 239 (40.8) | 143 (27.8) | 371 (35.7) | 11 (17.7) | |||||
| 2 | 242 (29.6) | 104 (36.6) | 177 (30.2) | 169 (32.8) | 332 (32.0) | 14 (22.6) | |||||
| 3 | 117 (14.3) | 62 (21.8) | 73 (12.5) | 106 (20.6) | 161 (15.5) | 18 (29.0) | |||||
| 4 | 53 (6.5) | 43 (15.1) | 25 (4.3) | 71 (13.8) | 78 (7.5) | 18 (29.0) | |||||
| GOLD stage | <0.001 | <0.001 | <0.001 | ||||||||
| I | 49 (6.0) | 11 (3.9) | 37 (6.3) | 23 (4.5) | 60 (5.8) | 0 (0) | |||||
| II | 262 (32.1) | 64 (22.5) | 220 (37.5) | 106 (20.6) | 316 (30.4) | 10 (16.1) | |||||
| III | 323 (39.5) | 101 (35.6) | 227 (38.7) | 197 (38.3) | 406 (39.1) | 18 (29.0) | |||||
| IV | 183 (22.4) | 108 (38.0) | 102 (17.4) | 189 (36.7) | 257 (24.7) | 34 (54.8) | |||||
Data are presented as mean ± SD or number (%). COPD, chronic obstructive pulmonary disease; ICU, intensive care unit; BMI, body mass index; CB, chronic bronchitis; mMRC, modified Medical Research Council; GOLD, Global Initiative for Chronic Obstructive Lung Disease.