Clinical characteristics and asthma disease burden of the main study population (including patients with SUEA) and the SUEA population: all ages (≥5 years) and the adult cohorts
| All patients (age ≥5 years)* | 18–64 years old | ≥65 years old | ||||
| Variable | All ages (n=3 63 558) | SUEA (n=2940) | All 18–64 years old (n=2 42 714) | SUEA (n=1900) | All ≥65 years old (n=95 189) | SUEA (n=983) |
| Blood eosinophil count, median (IQR) | 0.20 (0.11–0.35) | 0.40 (0.30–0.60) | 0.20 (0.12–0.34) | 0.40 (0.30–0.60) | 0.20 (0.10–0.30) | 0.40 (0.30–0.55) |
| Blood eosinophil count ≥0.3×109/L, n (%) | 156 136 (42.9) | 2940 (100) | 103 298 (42.6) | 1900 (100) | 37 629 (39.5) | 983 (100) |
| Female patients, n (% of females) | 91 865 (39.4) | 1952 (100) | 63 086 (39.8) | 1269 (100) | 22 010 (35.5) | 650 (100) |
| Male patients, n (% of males) | 64 271 (49.3) | 988 (100) | 40 212 (47.8) | 631 (100) | 15 619 (47.0) | 333 (100) |
| % Predicted PEF | ||||||
| Available data, n (%) | 277 334 (76.3) | 2614 (88.9) | 199 539 (82.2) | 1762 (92.7) | 77 795 (81.7) | 852 (86.7) |
| Mean (SD) | 77.4 (17.4) | 66.6 (18.6) | 79.2 (16.7) | 67.2 (18.5) | 72.8 (18.4) | 65.3 (18.8) |
| Mean daily SABA dosage (µg/day), n (%)† | ||||||
| 0 | 74 637 (20.5) | 610 (20.7) | 46 517 (19.2) | 354 (18.6) | 25 475 (26.8) | 250 (25.4) |
| 1–200 | 148 727 (40.9) | 315 (10.7) | 102 914 (42.4) | 180 (9.5) | 31 601 (33.2) | 132 (13.4) |
| 201–400 | 72 073 (19.8) | 504 (17.1) | 47 377 (19.5) | 286 (15.1) | 19 035 (20.0) | 211 (21.5) |
| >400 | 68 121 (18.7) | 1511 (51.4) | 45 906 (18.9) | 1080 (56.8) | 19 078 (20.0) | 390 (39.7) |
| Asthma therapy: GINA step, n (%)‡ | ||||||
| Step 1 | 58 159 (16.0) | 0 | 43 676 (18.0) | 0 | 8723 (9.2) | 0 |
| Step 2 | 115 346 (31.7) | 0 | 77 732 (32.0) | 0 | 26 297 (27.6) | 0 |
| Step 3 | 76 510 (21.0) | 59 (2.0) | 49 070 (20.2) | 40 (2.1) | 21 874 (23.0) | 17 (1.7) |
| Step 4 | 103 019 (28.3) | 2393 (81.4) | 67 661 (27.9) | 1547 (81.4) | 32 511 (34.2) | 798 (81.2) |
| Step 5 | 10 524 (2.9) | 488 (16.6) | 4575 (1.9) | 313 (16.5) | 5784 (6.1) | 168 (17.1) |
| Prescribed ICS during the baseline year, n (%) | 300 920 (82.8) | 2940 (100) | 196 640 (81.0) | 1900 (100) | 84 615 (88.9) | 983 (100) |
| Cumulative ICS dosage (µg/day), baseline year, median (IQR)† | 329 (132–658) | 1425 (1068–1967) | 301 (110–656) | 1421 (1068–1967) | 460 (230–874) | 1479 (1066–1967) |
| Last ICS dosage prescribed, per GINA classification, n (%)‡ | ||||||
| No ICS prescribed | 62 638 (17.2) | 0 | 46 074 (19.0) | 0 | 10 574 (11.1) | 0 |
| Low ICS dosage | 159 858 (44.0) | 114 (3.9) | 105 503 (43.5) | 75 (3.9) | 39 438 (41.4) | 35 (3.6) |
| Medium ICS dosage | 107 207 (29.5) | 943 (32.1) | 69 839 (28.8) | 569 (29.9) | 33 094 (34.8) | 330 (33.6) |
| High ICS dosage | 33 855 (9.3) | 1883 (64.0) | 21 298 (8.8) | 1256 (66.1) | 12 083 (12.7) | 618 (62.9) |
| ≥1 prescription during baseline, n (%) | ||||||
| Omalizumab | 3 (0) | 0 (0) | 3 (0) | 0 | 0 | 0 |
| LTRA | 21 436 (5.9) | 1001 (34.0) | 14 209 (5.9) | 743 (39.1) | 5092 (5.3) | 216 (22.0) |
| Theophylline | 6073 (1.7) | 397 (13.5) | 3333 (1.4) | 276 (14.5) | 2676 (2.8) | 116 (11.8) |
| Cumulative high-dosage ICS, n (%)† | 59 953 (16.5) | 2940 (100) | 34 463 (14.2) | 1900 (100) | 24 327 (25.6) | 983 (100) |
| Cumulative high-dosage ICS+LABA, n (%)† | 46 687 (12.8) | 2940 (100) | 27 526 (11.3) | 1900 (100) | 18 419 (19.3) | 983 (100) |
| Cumulative high-dosage ICS+LABA for 2 years, n (%)†§ | 34 898 (9.6) | 2940 (100) | 20 336 (8.4) | 1900 (100) | 14 128 (14.8) | 983 (100) |
| Maintenance OCS, n (%)¶ | 10 522 (2.9) | 488 (16.6) | 4573 (1.9) | 313 (16.5) | 5784 (6.1) | 168 (17.1) |
| Asthma attacks, mean (SD) | 0.31 (0.76) | 2.89 (1.32) | 0.30 (0.74) | 2.93 (1.35) | 0.36 (0.84) | 2.80 (1.27) |
| Median (range) | 0 (0–15) | 2 (2–14) | 0 (0–15) | 3 (2–14) | 0 (0–14) | 2 (2–13) |
| 0 attacks, n (%) | 288 836 (79.4) | 0 | 193 674 (79.8) | 0 | 73 362 (77.1) | 0 |
| 1 attack, n (%) | 50 675 (13.9) | 0 | 33 621 (13.9) | 0 | 14 229 (14.9) | 0 |
| 2–3 attacks, n (%)** | 20 793 (5.7) | 2307 (78.5) | 13 415 (5.5) | 1464 (77.1) | 6434 (6.8) | 800 (81.4) |
| ≥4 attacks, n (%)** | 3254 (0.9) | 633 (21.5) | 2004 (0.8) | 436 (22.9) | 1164 (1.2) | 183 (18.6) |
| Risk-domain asthma control, n (%) | 232 944 (64.1) | 244 (8.3) | 157 232 (64.8) | 151 (7.9) | 58 070 (61.0) | 90 (9.2) |
| Overall asthma control, n (%) | 149 349 (41.1) | 77 (2.6) | 100 694 (41.5) | 43 (2.3) | 36 490 (38.3) | 33 (3.4) |
| Cumulative high-dosage ICS+LABA and ≥2 attacks, n (%) | 8164 (2.2) | 2940 (100) | 5098 (2.1) | 1900 (100) | 2919 (3.1) | 983 (100) |
| Cumulative high-dosage ICS+LABA and ≥4 attacks, n (%) | 1569 (0.4) | 633 (21.5) | 1011 (0.4) | 436 (22.9) | 533 (0.6) | 183 (18.6) |
*All patients with SUEA included 14 children who were 5–11 years old and 43 adolescent patients 12–17 years old.
†SABA and cumulative ICS dosage exposure during the baseline year were calculated as the mean of recorded prescriptions over 365 days. High-dosage ICS was defined, using chlorofluorocarbon beclomethasone dipropionate-equivalent dose, according to 2014 British asthma guidelines as a cumulative beclomethasone-equivalent dosage of ≥800 µg/day for adults and ≥400 µg/day for children 5‒12 years.29
‡GINA treatment steps were defined using the last prescribed ICS dosage before the index date and applying low-dosage, medium-dosage and high-dosage ICS definitions per GINA guidelines (details in the online supplementary material).2
§Study definition of severe asthma, that is, cumulative high-dosage ICS+LABA during both baseline and outcome years.
¶Maintenance OCS at some time during the baseline year.
**The study definition of uncontrolled asthma was 2 or more attacks during the baseline year.
GINA, Global Initiative for Asthma; ICS, inhaled corticosteroid; IQR, interquartile range; LABA, long-acting β2-agonist; LTRA, leukotriene receptor antagonist; OCS, oral corticosteroids; PEF, peak expiratory flow; SABS, short-acting β2-agonist; SUEA, severe, uncontrolled eosinophilic asthma.