Demographics and baseline characteristics
| Interviewee baseline characteristics | Maintenance twice daily ICS plus as-needed salbutamol N=39 | As-needed budesonide-formoterol N=35 |
| Female | 44% | 66% |
| Age, years (mean: range) | 37.7: 19.0–69.0 | 43.5: 18.7–74.4 |
| Ethnicity, caucasian/other | 79%/21% | 75%/25% |
| Highest level of education, high school/postsecondary education | 26%/74% | 14%/86% |
| Asthma Control Questionnaire 5-item score (range 0–6) (mean±SD)‡ | 1.12±0.71 | 1.09±0.55 |
| FEV1% predicted (mean: range) | 93.1: 65–128 | 88.5: 61–121 |
| ≥1 Severe exacerbation in previous year* | 8% | 0% |
| Ever prescribed inhaled corticosteroid† | 64% | 71% |
Interviews were conducted on average 10.9 months (SD±0.7) (‘Maintenance’ group), 10.5 months (SD±0.9) (‘As-needed combination’ group) after randomisation in the 12-month RCT.
*Definition of severe asthma exacerbation: a. The use of systemic corticosteroids for at least 3 days because of asthma, or b. Hospitalisation or ED visit because of asthma, requiring systemic corticosteroids (0% of interviewees had an ED visit for asthma in the 12 months prior to RCT visit 1).
†Patients were not permitted to have taken inhaled corticosteroid in the 3 months prior to enrolment.
‡ACQ Score≥1.5=poor symptom control.
ACQ, Asthma Control Questionnaire; ED, emergency department; FEV1, forced expiratory volume in 1 second; RCT, randomised controlled trial.