The selection criteria for studies included in the meta-analysis2 were randomized controlled trials (RCTs) in which responses to the same drug were tested using different delivery devices, thus eliminating the influence of device/drug combinations. In the descriptions of the methods and subject inclusion criteria for the many studies we reviewed, patient ability to use the various devices was one of the variables frequently mentioned. One can only assume that an inability to use a device correctly excluded a subject from a trial, but also that correct inhaler technique was taught prior to study entry. The studies selected for analysis included trials in which devices were tested under conditions of actual clinical use (type 1 studies) or in a laboratory setting with well-trained subjects (type 2 studies). In the former, inhaler technique may have been reinforced on clinic visits but not monitored otherwise. Barnes and Crompton have stated that the use of correct inhaler technique in all studies analyzed resulted in our not discerning differences in efficacy between devices, and this may be true. However, the purpose of the meta-analysis was to test whether device performance influenced response, independent of drug, and with patients able to use the devices correctly. β2-Agonists were the test drugs for the majority of the RCTs, with doses sufficient to achieve the plateau of the dose-response curve. Only four studies of corticosteroids met the selection criteria for inclusion in the analysis; these RCTs compared metered-dose inhaler plus spacer to dry powder inhaler use in well-controlled adult asthmatics and showed no differences in response using either delivery device. It is possible that these results were only a consequence of patients using the correct inhaler technique. We do agree that poor inhaler technique is a contributing factor to loss of asthma control and would welcome RCTs comparing delivery devices in this population. We fully agree with Drs. Barnes and Crompton that a patient’s ability to use an aerosol delivery device correctly is an exceedingly important aspect when choosing an inhaler, and thank them for underscoring this point in their review of the guidelines.