Impact of Poorly Controlled Asthma on Acute Healthcare Utilization and Costs

Abstract

RATIONALE: Asthma is associated with considerable morbidity and costs. Few studies have quantified the impact of poorly controlled asthma on acute healthcare utilization and costs. This study quantifies the acute healthcare utilization and costs of patients with different degrees of asthma control (measured by the frequency of short-acting beta-agonist [SABA] used). METHODS: We used commercial administrative claims data to identify asthma patients aged 12-64 in 2006 (n = 50,908). Multivariate analyses were conducted to estimate the effect of SABA frequency in 2006 on asthma-specific emergency room (ER) use, hospitalizations, and costs in 2007, while controlling for baseline characteristics (e.g., demographics, comorbidities, asthma treatments, utilization, costs). RESULTS: Patients who used SABA frequently were significantly more likely to be hospitalized or use the ER in a dose-dependent fashion. Adjusted hospitalization rates were 9/1000 for patients who filled < 200 doses of SABA, 11/1000 for 201-400, 16/1000 for 401-800, and 24/1000 for > 800. Adjusted ER utilization rates were 14/1000 for < 200 doses, 25/1000 for 201-400, 44/1000 for 401-800, and 66/1000 for > 800. Adjusted asthma-specific healthcare costs were $448 for < 200 doses, $664 for 201-400, $993 for 401-800, and $1,679 for > 800. CONCLUSION: We found that the frequent use of SABA, starting at a low threshold, was a significant, consistent, and robust predictor of higher asthma-specific hospitalizations, ER use, and costs, even after controlling for other asthma treatments. This suggests that frequency of SABA use may be a good tool to identify asthma patients in need of intervention, as indicated in NHLBI guidelines.