Uncontrolled asthma in a commercially insured population from 2002 to 2007: trends, predictors, and costs.

OBJECTIVE: Uncontrolled asthma leads to preventable morbidity and increased health care utilization. The authors examined trends, predictors, and costs of uncontrolled asthma over 5 years in a large health plan population.

METHODS: The authors retrospectively examined administrative health claims data from mid-2000 to mid-2007 on patients with asthma aged 1 to 56 years (n = 54,653 patient-years, 28,595 unique patients). Uncontrolled asthma events were defined as > or =2 oral steroid fills or > or =5 short-acting beta(2)-agonist (SABA) fills over 12 months, or an asthma-related hospitalization or emergency department (ED) visit. Multivariate generalized mixed regression models determined patient- and neighborhood-level predictors for uncontrolled asthma events. The authors compared asthma-related costs for patients with and without uncontrolled asthma events.

RESULTS: In 2002-2003, 39% of patients had > or =1 uncontrolled asthma event. Most frequent were high use of rescue asthma medications. Asthma-related hospitalizations and ED visits were infrequent. The percentage having uncontrolled asthma events decreased significantly over time to 27% in 2006-2007, due to a decreased rate of frequent SABA fills. Males and adults > or =24 years had higher odds of medication-based uncontrolled asthma events, whereas residence in neighborhoods with more minorities and lower educational attainment was associated with ED visits or hospitalizations. Patients with uncontrolled asthma events had significantly higher asthma-related costs.

CONCLUSIONS: In this population, the proportion of patients with uncontrolled asthma, particularly as indicated by high SABA fills, decreased over a 5-year period. Several individual- and neighborhood-level characteristics were associated with uncontrolled asthma events. Clinicians and health plans can identify higher-risk patients in order to target asthma management strategies and reduce asthma-related morbidity and its associated costs.