Quantifying beta-agonist utilization: Occasions or puffs?

The Global Initiative for Asthma and the National Asthma Education and Prevention Program (NAEPP) both recommend assessing the frequency and number of inhalations of short-acting beta-agonists (SABAs) in asthma as important measures of asthma control and severity.1,2 Some ambiguity exists, though, as to whether to quantify SABA use as the number of puffs used or the number of “occasions” of use, and which measure best reflects the level of asthma control. In an effort to standardize outcome measures, the American Thoracic Society (ATS) and the European Respiratory Society (ERS) Task Force assessed the literature for the utility of these 2 measures of rescue medication use.3 They acknowledged that clinical trials reported SABA use as inhalations per day and proposed that practicing physicians should report SABA occasions, because patients may use 1 or 2 inhalations for rescue treatment. The albuterol package insert sections on clinical studies suggest 4 to 6 hours as the duration of an occasion based on clinical trials using 4-times daily SABA and measuring change in serial FEV1 and not for the treatment of acute symptoms.4 Events differ in duration by triggers that produce symptoms of varying intensity and duration and therefore the magnitude and duration of response to treatment is highly variable, further limiting the definition of an occasion.