Table 3. Patient characteristics of each exposed and unexposed group.
| Characteristics | Controls/Unexposed | Stepped-Down Drug | ||||||
|---|---|---|---|---|---|---|---|---|
| Not Stepped Down | ICSs | LABA | Other Add-on | |||||
| N | % | N | % | N | % | N | % | |
| Total | 85,460 | 100.0 | 32,785 | 100.0 | 4,078 | 100.0 | 3,018 | 100.0 |
| ICS stepdown | ||||||||
| Mean-daily ICS | – | – | 26,603 | 81.1 | – | – | – | – |
| Inhaler dose | – | – | 6,182 | 18.9 | – | – | – | – |
| Other add-on | ||||||||
| LTRA | – | – | . | . | – | – | 1,751 | 58.0 |
| Theophylline | – | – | . | . | – | – | 605 | 20.0 |
| LAMA | – | – | . | . | – | – | 662 | 21.9 |
| Age | ||||||||
| 18–29 | 10,936 | 12.8 | 4,503 | 13.7 | 522 | 12.8 | 273 | 9.0 |
| 30–40 | 13,303 | 15.6 | 5,899 | 18.0 | 610 | 15.0 | 418 | 13.9 |
| 40–50 | 16,403 | 19.2 | 6,984 | 21.3 | 710 | 17.4 | 594 | 19.7 |
| 50–60 | 14,603 | 17.1 | 5,691 | 17.4 | 661 | 16.2 | 624 | 20.7 |
| 60–70 | 14,367 | 16.8 | 4,817 | 14.7 | 673 | 16.5 | 537 | 17.8 |
| ≥70 | 15,848 | 18.5 | 4,891 | 14.9 | 902 | 22.1 | 572 | 19.0 |
| Males | 34,100 | 39.9 | 13,049 | 39.8 | 1,465 | 35.9 | 1,020 | 33.8 |
| Socioeconomic status | ||||||||
| 1 (least deprived) | 13,920 | 16.3 | 4,884 | 14.9 | 637 | 15.6 | 411 | 13.6 |
| 2 | 16,347 | 19.1 | 6,555 | 20.0 | 811 | 19.9 | 593 | 19.6 |
| 3 | 16,154 | 18.9 | 6,565 | 20.0 | 779 | 19.1 | 539 | 17.9 |
| 4 | 18,041 | 21.1 | 7,191 | 21.9 | 881 | 21.6 | 632 | 20.9 |
| 5 | 20,998 | 24.6 | 7,590 | 23.2 | 970 | 23.8 | 843 | 27.9 |
| BMI | ||||||||
| Normal | 18,120 | 23.0 | 7,350 | 24.0 | 873 | 22.7 | 630 | 21.9 |
| Underweight | 1,659 | 2.1 | 608 | 2.0 | 86 | 2.2 | 59 | 2.1 |
| Overweight | 32,929 | 41.8 | 12,802 | 41.8 | 1,544 | 40.2 | 1,157 | 40.3 |
| Obese | 26,163 | 33.2 | 9,876 | 32.2 | 1,335 | 34.8 | 1,026 | 35.7 |
| Smoking history | ||||||||
| Never | 27,822 | 32.6 | 10,799 | 32.9 | 1,264 | 31.0 | 967 | 32.0 |
| Current | 28,452 | 33.3 | 11,383 | 34.7 | 1,359 | 33.3 | 970 | 32.1 |
| Ex-smoker | 29,186 | 34.2 | 10,603 | 32.3 | 1,455 | 35.7 | 1,081 | 35.8 |
| Atopy | 46,104 | 53.9 | 17,917 | 54.6 | 2,283 | 56.0 | 1,842 | 61.0 |
| Anxiety | 18,836 | 22.0 | 6,816 | 20.8 | 1,031 | 25.3 | 777 | 25.7 |
| Depression | 22,921 | 26.8 | 8,582 | 26.2 | 1,227 | 30.1 | 946 | 31.3 |
| Reflux | 11,787 | 13.8 | 4,151 | 12.7 | 717 | 17.6 | 571 | 18.9 |
| In year prior to exposure | ||||||||
| ≥1 exacerbation | 8,204 | 9.6 | 2,750 | 8.4 | 526 | 12.9 | 585 | 19.4 |
| ICS frequency | ||||||||
| 3 | 18,328 | 21.4 | 6,582 | 20.1 | 937 | 23.0 | 350 | 11.6 |
| 4–6 | 37,611 | 44.0 | 17,467 | 53.3 | 1,924 | 47.2 | 1,123 | 37.2 |
| 7–10 | 19,439 | 22.7 | 6,410 | 19.6 | 833 | 20.4 | 930 | 30.8 |
| ≥11 | 10,082 | 11.8 | 2,326 | 7.1 | 384 | 9.4 | 615 | 20.4 |
| Max ICS | ||||||||
| Low dose | 48,136 | 56.3 | 16,266 | 49.6 | 1,647 | 40.4 | 937 | 31.0 |
| Medium dose | 26,969 | 31.6 | 11,295 | 34.5 | 1,669 | 40.9 | 1,010 | 33.5 |
| High dose | 10,355 | 12.1 | 5,224 | 15.9 | 762 | 18.7 | 1,071 | 35.5 |
| Stable ICS | 68,671 | 80.4 | 26,300 | 80.2 | 2,875 | 70.5 | 2,242 | 74.3 |
| LABA use | 46,256 | 54.1 | 15,464 | 47.2 | 0 | 0.0 | 2,478 | 82.1 |
| ≥2 add-on therapies | 686 | 0.8 | 185 | 0.6 | 23 | 0.6 | 528 | 17.5 |
| Reliever frequency | ||||||||
| 0–2 | 27,764 | 32.5 | 12,094 | 36.9 | 1,560 | 38.3 | 809 | 26.8 |
| 3–7 | 36,874 | 43.1 | 15,077 | 46.0 | 1,770 | 43.4 | 1,177 | 39.0 |
| ≥8 | 20,822 | 24.4 | 5,614 | 17.1 | 748 | 18.3 | 1,032 | 34.2 |
| Annual asthma review | 45,893 | 53.7 | 15,775 | 48.1 | 2,136 | 52.4 | 1,558 | 51.6 |
| Inhaler technique | 37,633 | 44.0 | 13,517 | 41.2 | 1,807 | 44.3 | 1,246 | 41.3 |
| Asthma management plan | 9,673 | 11.3 | 3,080 | 9.4 | 479 | 11.7 | 297 | 9.8 |
Dashes indicate no data/not applicable. Abbreviations: BMI, body mass index; ICS, inhaled corticosteroid; LABA, long-acting β2-agonist; LAMA, long-acting muscarinic antagonist.