I write with regard to the article by Harrisonet al 1 who described their findings of reducing β agonist use in asthma patients with a methodology involving placebo inhalers. This study describes an interesting design as well as interesting outcomes with an apparent reduction in β agonist use without loss of control.

There are several pieces of information which would make the article more useful in understanding how widely these results may be extrapolated. Firstly, the baseline inhaled corticosteroid use and the distribution between the two groups is important information. It would also help if the authors of the paper could clarify whether the patients continued on their usual maintenance inhaled corticosteroids throughout the study and whether the budesonide that was added at weeks 4–6 was in addition to baseline steroid use. The next issue concerns the instructions the patients were given about the use of β agonists. How many of them were told to use doses on a four times a day basis rather than as required? I also would like to know the proportion of patients who recognised they were receiving placebo with no active medication compared with those who were not aware that they had been switched to placebo. Finally, were specific instructions given to patients that they might need to ignore some some symptoms of breathlessness to enable the reduction in the use of β agonists?

The above information would be helpful in understanding more completely the population and how applicable this dosage reduction scheme may be to other patients with asthma.