Clinical characteristic according to different airflow obstruction classifications
| COPD-X* | Mild (n=35) | Moderate (n=96) | Severe (n=102) | Very severe | |
| Sex | Male | 18 (51%) | 49 (51%) | 57 (56%) | – |
| Age | Years (mean (95% CI)) | 57.11 (53.01 to 61.21) | 56.12 (53.51 to 58.74) | 52.59 (50.53 to 54.65) | – |
| BMI | kg/m2 (median (IQR)) | 24.54 (19.53–28.35) | 24.64 (20.94–29.66) | 21.19 (17.06–24.84) | – |
| Smoking status | Never smoker | 1 (3%) | 12 (13%) | 5 (5%) | – |
| Former smoker | 10 (29%) | 41 (43%) | 43 (42%) | – | |
| Current smoker | 24 (69%) | 43 (45%) | 54 (53%) | – | |
| Smoking pack years (median (IQR)) | 30 (15.5–43.75) | 12.5 (5.38–40) | 26.35 (11.13–39.38) | – | |
| COPD | Clinical history of COPD | 25 (71%) | 59 (64%) | 76 (77%) | – |
| Mortality | Deceased (all cause) | 2 (6%) | 10 (10%) | 26 (25%) | – |
| Deceased age (years) (mean (95% CI)) | 62.39 to 75.3 | 65.27 (57.02 to 73.52) | 54.07 (49.98 to 58.15) | – | |
| GOLD | Mild (n=5) | Moderate (n=78) | Severe (n=97) | Very severe (n=58) | |
| Sex | Male | 3 (60%) | 41 (53%) | 52 (54%) | 31 (53%) |
| Age | Years (mean (95% CI)) | 52.02 (27.88 to 76.17) | 55.94 (53.14 to 58.74) | 55.88 (53.43 to 58.32) | 51.16 (48.53 to 53.78) |
| BMI | kg/m2 (median (IQR)) | 27.6 (22.27–38.57) | 24.5 (20.28–28.35) | 23.28 (19.08–28.97) | 21.74 (17.01–24.54) |
| Smoking status | Never smoker | 2 (40%) | 8 (10%) | 7 (7%) | 3 (5%) |
| Former smoker | 1 (20%) | 22 (28%) | 47 (48%) | 25 (43%) | |
| Current smoker | 2 (40%) | 48 (62%) | 43 (44%) | 30 (52%) | |
| Smoking pack years (median (IQR)) | 11.25 (4.5–112.5) | 23 (8–45) | 18 (5.1–37.5) | 27.5 (14.7–38.75) | |
| COPD | Clinical history of COPD | 1 (20%) | 50 (64%) | 66 (70%) | 44 (76%) |
| Mortality | Deceased (all cause) | 0 (0%) | 6 (8%) | 15 (15%) | 17 (29%) |
| Deceased age (years) (mean (95% CI)) | 66.05 (52.67 to 79.42) | 62.54 (57.19 to 67.9) | 50.69 (46.1 to 55.28) | ||
| GLI-2012 | Mild (n=16) | Moderate (n=43) | Severe (n=83) | Very severe (n=96) | |
| Sex | Male | 9 (56%) | 19 (44%) | 44 (53%) | 51 (53%) |
| Age | Years (mean (95% CI)) | 55.41 (47.52 to 63.29) | 57.85 (53.86 to 61.83) | 54.53 (51.98 to 57.07) | 48.35 (46.31 to 50.39) |
| BMI | kg/m2 (median (IQR)) | 23.64 (21.2–27.8) | 24.54 (20.2–28.98) | 23.99 (19.61–29.02) | 22.03 (17.21–25.81) |
| Smoking status | Never smoker | 2 (13%) | 3 (7%) | 6 (7%) | 6 (6%) |
| Former smoker | 4 (25%) | 18 (42%) | 37 (45%) | 39 (41%) | |
| Current smoker | 10 (63%) | 22 (51%) | 40 (48%) | 51 (53%) | |
| Smoking pack years (median (IQR)) | 33 (11.25–60) | 21 (8–37.5) | 12.5 (5–40) | 20 (7–37.5) | |
| COPD | Clinical history of COPD | 8 (50%) | 32 (74%) | 50 (62%) | 66 (72%) |
| Mortality (all cause) | Deceased (all cause) | 1 (6%) | 3 (7%) | 10 (12%) | 21 (22%) |
| Deceased age (years) (mean (95% CI)) | 75.3 | 62.15, 62.39 to 85.35 | 64.12 (57.43 to 70.8) | 51.14 (47.11 to 55.18) | |
*Five patients excluded from COPD-X as FEV1 was >80%.
BMI, body mass index; COPD, chronic obstructive pulmonary disease; COPD-X, concise tool for chronic obstructive pulmonary disease; FEV1, forced expiratory volume in 1 s; GLI, global lung function initiative; GOLD, global initiative for chronic obstructive lung disease.