Table 1.
Baseline Patient Characteristics, Stratified by Exacerbation Risk
| Variable | Overall Cohort (N = 738) | Low-Risk Groups A and B (n = 571) |
High-Risk Groups C and D (n = 167) |
|---|---|---|---|
| Demographics | |||
| Age, y | 68.8 ± 7.5 | 69.0 ± 7.5 | 68.1 ± 7.4 |
| Male | 542 (73.4) | 422 (73.9) | 120 (71.9) |
| BMI, kg/m2 | 28.6 ± 6.5 | 28.4 ± 6.6 | 29.2 ± 5.7 |
| Current smoker | 202 (27.4) | 165 (28.9) | 37 (22.2) |
| Pack-year history | 61.4 ± 32.9 | 61.5 ± 32.7 | 61.0 ± 33.9 |
| Randomized to oxygen | 368 (49.9) | 287 (50.2) | 81 (48.5) |
| 24-h oxygen | 220 (29.8) | 170 (29.8) | 50 (29.9) |
| Nocturnal/ambulatory oxygen only | 148 (20.0) | 117 (20.4) | 31 (18.6) |
| Indication for supplemental oxygen | |||
| Resting Spo2 88%-94% | 133 (18.0) | 105 (18.4) | 28 (16.8) |
| Ambulatory Spo2 80%-88% | 319 (43.2) | 239 (41.9) | 80 (47.9) |
| Both | 286 (38.8) | 227 (39.8) | 59 (35.3) |
| Charlson comorbidity index score | 5.0 ± 1.9 | 5.0 ± 1.9 | 4.9 ± 1.9 |
| Prior pneumonia | 394 (53.4) | 283 (49.6) | 111 (66.5) |
| Pulmonary rehabilitation | 220 (29.8) | 157 (27.5) | 63 (37.7) |
| COPD severity | |||
| BODE indexa | |||
| 0-2 | 165 (22.7) | 136 (24.2) | 29 (17.5) |
| 3-4 | 282 (38.7) | 217 (38.6) | 65 (39.2) |
| 5-6 | 210 (28.8) | 155 (27.6) | 55 (33.1) |
| 7-10 | 71 (9.8) | 54 (9.6) | 17 (10.2) |
| GOLD stage | |||
| I | 26 (3.5) | 24 (4.2) | 2 (1.2) |
| II | 244 (33.1) | 185 (32.4) | 59 (35.3) |
| III | 357 (48.4) | 279 (48.9) | 78 (46.7) |
| IV | 111 (15.0) | 83 (14.5) | 28 (16.8) |
| Exacerbations in past 3 mo | 0.3 ± 0.6 | 0.0 ± 0.0 | 1.1 ± 0.9 |
| Baseline SGRQ total score | 50.0 ± 17.9 | 48.9 ± 17.9 | 53.8 ± 17.7 |
| Baseline 6MWT distance, m | 318 ± 99 | 322 ± 101 | 307 ± 91 |
Values are mean ± SD or No. (%). 6MWT = 6-min walk test; GOLD = Global Initiative for Chronic Obstructive Lung Disease; SGRQ = St. George’s Respiratory Questionnaire; Spo2 = pulse oximetry oxygen saturation.
a
n = 728; 10 patients could not complete baseline 6MWT.