Does continuous use of inhaled corticosteroids improve outcomes in mild asthma? A double-blind randomised controlled trial

Aim: To compare the effects of fluticasone and placebo on asthma control in patients with mild asthma.

Method: Adults with FEV1 >80% predicted and reliever use ≤2 times/week were randomised to receive fluticasone 250 mcg/day or placebo double-blind for 11 months. Exacerbations were treated with four weeks' fluticasone 500 mcg/day. Primary outcomes were electronically-recorded morning PEF and FEV1, analysed by mixed model regression.

Results: 44 subjects were randomised (23-fluticasone, 21-placebo). Fluticasone led to significantly better morning FEV1 (mean difference 5.4% predicted, p<0.0001), morning PEF, clinic spirometry, exhaled nitric oxide levels, and airway hyperresponsiveness, but there were no differences in reliever use, symptoms or quality of life. Fewer patients had mild exacerbations on fluticasone (22% vs 62%, p=0.02).

Conclusion: The goals of asthma treatment include not only control of symptoms, but also prevention of future adverse outcomes such as exacerbations — which can occur even in mild asthma. This study showed that treatment with low dose inhaled corticosteroids led to significant improvements in lung function, exacerbations, and in pathophysiological predictors of future risk, even though symptoms were minimal at entry. For patients with mild asthma, discussion about treatment needs to consider not only short-term benefit, side effects and cost, but also long-term reduction of risk.

This study was completed prior to mandatory registration for clinical trials.