Characteristics of patients with COPD by frequency of recorded exacerbation episodes during 12-month follow-up
| Moderate-to-severe exacerbation frequency | |||
|---|---|---|---|
| None | One | Two or more | |
| Patient characteristic | n=31 049 | n=14 189 | n=13 351 |
| Age, mean (SD) | 69.3 (10.5) | 69.8 (10.3) | 69.4 (10.2) |
| Smoking status | |||
| Current | 10 531 (34) | 4667 (33) | 4173 (31) |
| Former | 15 988 (51) | 7474 (53) | 7345 (55) |
| Never | 3312 (11) | 1492 (11) | 1301 (10) |
| Other | 1218 (4) | 556 (4) | 532 (4) |
| Female | 13 619 (44) | 6831 (48) | 6832 (51) |
| BMI underweight (<18.5 kg/m2) | 1327 (4) | 641 (5) | 751 (6) |
| BMI normal (18.5–24.9 kg/m2) | 10 533 (34) | 4810 (34) | 4668 (35) |
| BMI overweight (25.0–29.9 kg/m2) | 10 633 (34) | 4778 (34) | 4274 (32) |
| BMI obese (≥30.0 kg/m2) | 8037 (26) | 3760 (26) | 3472 (26) |
| Rate of moderate-to-severe exacerbations in prior 12 months/person/year, mean | 0.37 | 0.74 | 1.67 |
| Rate of exacerbations with hospital admission in prior 12 months/person/year, mean | 0.07 | 0.12 | 0.2 |
| Comorbidities any time in history | |||
| Acute myocardial infarction | 2530 (8) | 1386 (10) | 1350 (10) |
| Congestive heart disease | 1857 (6) | 1041 (7) | 1165 (9) |
| Depression | 3976 (13) | 2116 (15) | 2393 (18) |
| ≥1 prescription within 12 months before cohort entry | |||
| ICS | 5789 (19) | 2883 (20) | 2501 (19) |
| LABA | 2379 (8) | 1278 (9) | 1295 (10) |
| ICS/LABA | 12 150 (39) | 7328 (52) | 9133 (68) |
| LAMA | 8618 (28) | 5260 (37) | 7049 (53) |
| MRC dyspnoea scale score | |||
| MRC 1 | 6251 (23) | 2059 (16) | 1165 (10) |
| MRC 2 | 11 552 (42) | 4765 (38) | 3546 (31) |
| MRC 3 | 6478 (23) | 3487 (28) | 3286 (29) |
| MRC 4 | 2959 (11) | 1876 (15) | 2605 (23) |
| MRC 5 | 524 (2) | 398 (3) | 690 (6) |
| Airflow limitation grade | |||
| Mild | 5475 (18) | 1971 (14) | 1398 (10) |
| Moderate | 16 815 (54) | 7324 (52) | 5693 (43) |
| Severe | 7013 (23) | 3855 (27) | 4629 (35) |
| Very severe | 1152 (4) | 814 (6) | 1411 (11) |
All data are n (%) unless otherwise stated. Percentages expressed as column %.
BMI, body mass index; COPD, chronic obstructive pulmonary disease; ICS, inhaled corticosteroid; LABA, long-acting β2-agonist; LAMA, long-acting muscarinic antagonist; MRC, Medical Research Council.