Inhaled corticosteroid adherence and emergency department utilization among Medicaid-enrolled children with asthma

Objectives: Asthma is the most prevalent chronic disease among children enrolled in Medicaid. This study measured real-world adherence and outcomes after an initial prescription for inhaled corticosteroid therapy in a multi-state Medicaid population. Methods: We conducted a retrospective study among Medicaid-enrolled children aged 5-12 years with asthma in 14 southern states using 2007 Medicaid Analytic eXtract file claims data to assess adherence and outcomes over the 3 months following an initial prescription drug claim for inhaled corticosteroids (ICS-Rx). Adherence was measured by the long-term controller-to-total asthma drug claims ratio. Results: Only one-third of children (33.4%) with an initial ICS-Rx achieved a controller-to-total drug ratio >0.5 over the next 90 days. Children for whom long-term control drugs represented less than half of their total asthma drug claims had a 21% higher risk of emergency department (ED) visit (adjusted odds ratio (AOR) 1.21 [95% CI 1.14, 1.27]), and a 70% higher risk of hospital admission (AOR 1.70 [95% CI 1.45, 1.98]) than those with a controller-to-total asthma drug ratio >0.5. Conclusion: Real-world adherence to long-term controller medications is quite low in this racially diverse, low-income segment of the population, despite Medicaid coverage of medications. Adherence to long-term controller therapy had a measurable impact on real-world outcomes. Medicaid programs are a potential surveillance system for both medication adherence and ED utilization.