Utilization, spending, and price trends for short- and long-acting beta-agonists and inhaled corticosteroids in the Medicaid program, 1991-2010

Background: Asthma is a chronic respiratory disease that afflicts millions of people and accounts for substantial utilization of healthcare resources in most industrialized countries, including in the United States. However, the exact cost and utilization of anti-asthma medications in Medicaid in the past 2 decades have not been well studied. Considering the safety issues surrounding the long-acting beta-agonists, guideline updates, and the increase in asthma prevalence, understanding anti-asthma medication prescribing trends is important to payers and patients. Goal: The purpose of this study was to analyze the utilization and spending trends for antiasthmatic agents in the US Medicaid program over the past 2 decades. Methods: This study was based on a retrospective, descriptive analysis of trends in utilization of and spending on anti-asthma medications, including short-acting beta-agonists, inhaled corticosteroids, long-acting beta-agonists, and inhaled corticosteroid/long-acting betaagonist combinations. Quarterly utilization and expenditure data were obtained from the national Medicaid pharmacy files provided by the Centers for Medicare & Medicaid Services from quarter 1 of 1991 through quarter 2 of 2010. Average reimbursement per prescription was calculated each quarter as a proxy for drug price. Results: The total number of prescriptions for the studied anti-asthma medications rose from 8.9 million in 1991 to 15.6 million in 2009, peaking at 20.8 million in 2005, the year before Medicare and Medicaid dual-eligible beneficiaries were moved to Medicare Part D. From 1991 to 2009, Medicaid spending on anti-asthma medications overall rose from $180.7 million to $1.3 billion, and spending on inhaled corticosteroid/long-acting beta-agonist combinations rose from $52.8 million in 2001-their first year on the market-to $411.7 million in 2009. The average price per prescription has risen in all the anti-asthma drug classes: overall, spending per prescription has increased 4-fold between 1991 and 2009, significantly faster than the consumer price index (57.5%) over the same period. In quarter 2 of 2010, Medicaid spent more on the combination medication fluticasone-salmeterol-$60 million-than on any other antiasthma medication. Conclusion: Anti-asthma medications are a major and growing expense for state Medicaid programs and can be expected to be the same for Medicare Part D in the future. Increased disease prevalence has in part contributed to the rise in pharmacotherapy cost. Nevertheless, drug therapy is crucial for managing asthma and asthma exacerbations.