Patient demographics at baseline# among patients with asthma in Nova Scotia and Alberta
| Primary study cohort | ||
| Nova Scotia | Alberta | |
| Subjects, n | 8034 | 107 444 |
| Follow-up, median (IQR) (days) | 442 (386–490) | 730 (730–730) |
| Sex, n (%) | ||
| Male | 3171 (39.5) | 46 910 (43.7) |
| Female | 4863 (60.5) | 60 534 (56.3) |
| Age (years) | ||
| Mean±sd | 43.4±18.3 | 39.7±17.1 |
| Median (IQR) | 43.0 (29.0–57.0) | 38.0 (26.0–52.0) |
| Elixhauser comorbidity score, mean±sd | 2.01±1.27 | 1.21±1.07 |
| Asthma severity, n (%) | ||
| Mild asthma | 6694 (83.3) | 91 189 (84.9) |
| Mild, no prescription | 880 (11.0) | 29 353 (27.3) |
| Mild, excluding those with no prescription | 5814 (72.4) | 61 836 (57.6) |
| Moderate asthma | 998 (12.4) | 10 412 (9.7) |
| Severe asthma, no biological treatment | 342 (4.3) | 5843 (5.4) |
| All outpatient visits | ||
| Mean±sd | 1.9±1.3 | 1.6±2.8 |
| Median (IQR) | 2.0 (1.0–2.0) | 1.0 (0.0–2.0) |
| Asthma-specific prescriptions | ||
| Mean±sd | 5.4±5.1 | 5.0±4.5 |
| Median (IQR) | 4.0 (2.0–8.0) | 4.0 (2.0–7.0) |
| Exacerbations,¶ n (%) | ||
| ED visits | ||
| 0 | 7922 (98.6) | 102 098 (95.0) |
| 1 | 100 (1.2) | 4341 (4.0) |
| 2 | 11 (0.1) | 709 (0.7) |
| 3 | <5 (0) | 176 (0.2) |
| 4+ | <5 (0) | 62 (0.1) |
| Hospitalisations (excluding ED visits) | ||
| 0 | 8033 (100) | 106 303 (98.9) |
| 1 | <5 (0) | 1071 (1.0) |
| 2 | <5 (0) | 58 (0.1) |
| 3 | <5 (0) | 11 (0.0) |
| 4+ | <5 (0) | <5 (0) |
| Prescriptions for OCS | ||
| 0 | 6171 (76.8) | 93 070 (86.6) |
| 1 | 1210 (15.1) | 10 054 (9.4) |
| 2 | 375 (4.7) | 2501 (2.3) |
| 3 | 129 (1.6) | 882 (0.8) |
| 4+ | 149 (1.9) | 937 (0.9) |
| Severe exacerbations+ | ||
| 0 | 6149 (76.5) | 95 030 (88.4) |
| 1 | 1218 (15.2) | 8855 (8.2) |
| 2 | 381 (4.7) | 2150 (2.0) |
| 3 | 137 (1.7) | 699 (0.7) |
| 4+ | 149 (1.9) | 710 (0.7) |
Cohorts include patients with an asthma diagnosis identified between 2016 and 2020 within two provincial administrative datasets (Health Data Nova Scotia and Alberta Health Services). ED: emergency department; OCS: oral corticosteroid. #: 1 year following diagnosis; ¶: unique visit dates and/or admission dates; +: if more than one of the events (hospitalisation or ED with primary diagnosis of asthma, or oral corticosteroid) occurred within a 2-week window, this was counted as one exacerbation.