Long-acting β-agonist monotherapy among children and adults with asthma

To determine the prevalence of long-acting β-agonist (LABA) monotherapy among a Medicaid-enrolled population with asthma and to describe continued LABA monotherapy use.

Retrospective cohort.

Administrative Medicaid claims data for Michigan were used to identify children and adults with asthma, defined as having 4 or more asthma medication–dispensing events during a calendar year between 2006 and 2008. We determined the annual prevalence of LABA monotherapy, defined as having at least 1 dispensing event for a LABA medication in the absence of any other maintenance therapy. The cohort using LABA monotherapy was followed up for 12 months after the identification year to assess continued LABA monotherapy and the frequency of missed opportunities for changes in therapy. Analyses included prevalence proportions, median numbers of office visits, and χ(2) tests to test for significant differences between subgroups.

LABA monotherapy among persons with asthma was uncommon (<1%) and decreased over time. LABA monotherapy was more prevalent among female subjects, persons of white race, and older age groups. The prevalence of continued LABA monotherapy during the followup year was 41.2% among the cohort of LABA monotherapy users. Most users of continued LABA monotherapy (92.9%) had at least 1 missed opportunity for therapy change or patient education during the follow-up period.

Although our results indicate that LABA monotherapy was rare, this study provides further evidence supporting enhanced information sharing between points of service about medication utilization that is inconsistent with accepted guidelines.