Doubling the dose of inhaled corticosteroid to prevent asthma exacerbations: randomised controlled trial.

BACKGROUND Asthma self-management plans that include doubling the dose of inhaled corticosteroid when the condition deteriorates improve asthma control. Whether doubling the dose of corticosteroid in isolation is effective is unknown. We undertook a randomised controlled trial to investigate the effects of doubling the dose of inhaled corticosteriods when asthma deteriorates. METHODS 390 individuals with asthma who were at risk of an exacerbation monitored their morning peak flow and asthma symptoms for up to 12 months. When peak flow or symptoms started to deteriorate, participants added an active or placebo corticosteroid inhaler to their usual corticosteroid for 14 days to produce a doubling or no change in dose. The primary outcome was the number of individuals starting oral prednisolone in each group. FINDINGS During 12 months, 207 (53%) started their study inhaler and 46 (12%) started prednisolone--22 (11%) of 192 and 24 (12%) of 198 in the active and placebo groups, respectively. The risk ratio for starting prednisolone was therefore 0.95 (95% CI 0.55-1.64, p=0.8). INTERPRETATION We recorded little evidence to support the widely recommended intervention of doubling the dose of inhaled corticosteroid when asthma control starts to deteriorate.