Oborne 2009.

Study characteristics
Methods	Randomised, double‐blind, placebo‐controlled, parallel‐group trial Single centre based in the UK Investigated whether a 4‐fold increase in the dose of inhaled corticosteroids, started when asthma control deteriorates, can prevent the need for oral corticosteroids Recruitment between 2004 and 2008 52 weeks from baseline to endpoint
Participants	Population 403 participants were randomised; 94 participants experienced an exacerbation, for a total of 121 exacerbations that contributed to the analysis. Participants were 16 years of age or older; mean age was 56 years; 32% of participants were male; 69% were never‐smokers, 21% were ex‐smokers, and 10% were smokers. Inclusion criteria: age > 16 years, stable asthma, treated with ICS (200 to 1000 μg budesonide or equivalent), taken a course of oral corticosteroid or doubled dose of ICS in the previous 12 months but not in the preceding 4 weeks Exclusion criteria: > 20 pack‐year smoking history, other clinically significant medical conditions, pregnant or lactating Baseline asthma severity See Table 2.
Interventions	Run‐in period: 2‐week period whereby participants continued their usual dose of inhaled corticosteroid and recorded morning peak flow and daytime symptom scores to ensure asthma stability Study period Control arm: maintenance inhaled corticosteroid (200 to 1000 μg/d) + identical placebo inhaler for exacerbations Study arm: maintenance inhaled corticosteroid (200 to 1000 μg/d) + identical inhaler with corticosteroid to quadruple dose of ICS for exacerbations Participants were to use study inhaler for 14 days in addition to usual treatment when peak flow or symptoms deteriorated. Other medications allowed Not specified
Outcomes	Primary outcome Number of participants who had exacerbations of asthma treated with oral corticosteroids (ITT analysis) Secondary outcomes Number of participants who started the study inhaler and went on to require treatment with oral corticosteroids (treated population)
Notes	Funding source: Asthma UK Funder role: not reported Registration:ISRCTN46018181 Ethics approval: approved by Nottingham Research Ethics Committee and relevant Research and Development departments in Nottinghamshire and Derbyshire Consent to participate: reports that participants provided written informed consent Trial reporting vs review analysis: study reports the need for oral steroids separately for those who took their study inhaler (suitable for Analysis 1.2) and all randomised participants (suitable for Analysis 1.1)