Patient demographics and clinical assessments by physician-assigned diagnosis
| Asthma | Asthma+COPD | COPD | Total sample | |
| Patients | 510 | 510 | 510 | 1530 |
| Age years | 52.7±15.5 | 65.6±9.7 | 67.3±9.6 | 61.8±13.6 |
| Sex | ||||
| Female | 327 (64.1) | 230 (45.1) | 196 (38.4) | 753 (49.2) |
| Male | 183 (35.9) | 280 (54.9) | 314 (61.6) | 777 (50.8) |
| Ethnicity | ||||
| African-American | 22 (4.3) | 19 (3.7) | 21 (4.1) | 62 (4.1) |
| Caucasian | 371 (72.7) | 395 (77.5) | 424 (83.1) | 1190 (77.8) |
| North East Asian | 38 (7.5) | 24 (4.7) | 5 (1.0) | 67 (4.4) |
| South East Asian | 8 (1.6) | 3 (0.6) | 3 (0.6) | 14 (0.9) |
| Other | 71 (13.9) | 69 (13.5) | 57 (11.2) | 197 (12.9) |
| Time since diagnosis years | ||||
| Patients with non-missing data | 324 (63.5) | 379 (74.3) | 363 (71.2) | 1066 (69.7) |
| Mean±sd | 15.4±16.1 | 14.7±16.8 | 7.0±6.6 | 12.3±14.4 |
| Physician-assessed severity# | ||||
| Mild | 188 (36.9) | 90 (17.6) | 122 (23.9) | 400 (26.1) |
| Moderate | 186 (36.5) | 223 (43.7) | 150 (29.4) | 559 (36.5) |
| Severe | 136 (26.7) | 197 (38.6) | 238 (46.7) | 571 (37.3) |
| Post-BD FEV1 % pred | ||||
| Patients with non-missing data | 408 (80.0) | 432 (84.7) | 417 (81.8) | 1257 (82.2) |
| Mean±sd | 85.6±19.7 | 66.7±21.7 | 58.3±22.3 | 70.1±24.1 |
| SGRQ total score¶ | ||||
| Patients with non-missing data | 507 (99.4) | 508 (99.6) | 507 (99.4) | 1522 (99.5) |
| Mean±sd | 29.8±21.0 | 40.2±22.4 | 41.9±22.0 | 37.3±22.4 |
| mMRC dyspnoea scale grade+ | ||||
| Patients with non-missing data | 490 (96.1) | 496 (97.3) | 498 (97.6) | 1484 (97.0) |
| Mean±sd | 0.9±0.9 | 1.5±1.0 | 1.7±1.1 | 1.4±1.1 |
| ACT score§ | ||||
| Patients with non-missing data | 495 (97.1) | 454 (89.0) | NA | 949 (62.0) |
| Mean±sd | 19.6±4.5 | 17.6±5.1 | NA | 18.6±4.9 |
| RSQ scoreƒ | ||||
| Patients with non-missing data | 510 (100.0) | 510 (100.0) | 510 (100.0) | 1530 (100.0) |
| Mean±sd | 4.4±3.8 | 6.4±4.4 | 6.0±4.3 | 5.6±4.3 |
Data are presented as n, mean±sd or n (%). COPD: chronic obstructive pulmonary disease; BD: bronchodilator; FEV1: forced expiratory volume in 1 s; SGRQ: St George's Respiratory Questionnaire; mMRC: modified Medical Research Council; ACT: Asthma Control Test; NA: not applicable; RSQ: Respiratory Symptoms Questionnaire. #: for patients with asthma+COPD, severity was allocated as the higher of the two severity categories assigned by the physician for their asthma and their COPD; ¶: range 0–100; +: range 0–4; §: range: 5–25; ƒ: valid scoring of the RSQ requires that all items have been completed and the sum score (range 0–16) is used (the total scores of individuals with missing values for any item were treated as missing and only patients with valid RSQ scores were randomly selected for this analysis).