Characteristics of study population over a 12 month period
| Patients selected from asthma clinics(n = 71) | Quebec cohort of asthmatic patients*(n = 139 283 person-years) | |
|---|---|---|
| ICS, inhaled corticosteroid; SABA, short-acting β2 agonist; LABA, long-acting β2 agonist; ED, emergency department. | ||
| *On average, patients contributed 2.1 episodes of 1 year into the cohort. The cohort comprises patients with asthma selected from 1 January 1997 to 31 December 2004. | ||
| †ICS daily dose in beclomethasone-chlorofluorocarbon equivalent over a 12 month period. | ||
| ‡Average number of inhaled short-acting β2 agonist doses per week calculated over a 12 month period. | ||
| Mean (SD) age (years) | 49.0 (17.8) | 30.3 (8.7) |
| Women (%) | 62.9 | 62.2 |
| ICS use, μg per day (%)† | ||
| 0 | 28.2 | 37.0 |
| 1–250 | 15.5 | 34.3 |
| 251–500 | 18.3 | 11.9 |
| 501–1000 | 18.3 | 10.9 |
| >1000 | 19.7 | 5.9 |
| SABA, number of doses per week (%)‡ | ||
| 0–3 | 57.7 | 53.6 |
| 4–10 | 15.5 | 22.4 |
| >10 | 26.8 | 24.0 |
| LABA use (%) | 54.9 | 23.4 |
| Theophylline use (%) | 9.9 | 2.3 |
| Leucotriene receptor antagonist use (%) | 21.1 | 7.7 |
| Oral corticosteroid use (%) | 31.0 | 16.5 |
| Respiratory physician visit (%) | 98.6 | 12.3 |
| ED care for asthma (%) | 11.3 | 18.1 |
| Hospital care for asthma (%) | 4.2 | 6.2 |