A population-based study of adults who frequently visit the emergency department for acute asthma. California and Florida, 2009-2010.

Rationale: Little is known about adults who frequently visit the emergency department (ED) for acute asthma, or the economic impact of this ED use.
Objectives: To examine the proportion and patient characteristics of adult patients with multiple ED visits for acute asthma and the associated hospital charges.
Methods: We analyzed population-based data from the Healthcare Cost and Utilization Project state ED and inpatient databases for two large states (California and Florida) between 2009 and 2010. We focused on adult asthma patients with asthma-related ED visits. Hospital charge data were available only for Florida.
Measurements and Main Results: The final cohort comprised 86,224 unique patients with 131,907 asthma-related ED visits. Within 1 year of the first ED visit, 26% (95% confidence interval, 25-26%) of patients had multiple (two or more) ED visits. In a multivariable model adjusting for comorbidities, significant predictors of multiple ED visits were black race, Hispanic ethnicity, and low socioeconomic status (all P < 0.05). In multivariate modeling in finer categories of ED visit number, increasingly stronger associations were found for higher numbers of asthma-related ED visits. Total charges were $346 million in Florida; patients with multiple ED visits accounted for 57% (95% confidence interval, 51-62%) of total charges.
Conclusions: In this population-based cohort, 26% of patients had multiple asthma-related ED visits within 1 year. These patients were more likely to be black, Hispanic, and of lower socioeconomic status; they accounted for 57% of asthma-related hospital charges in Florida. To improve population health and to control asthma-related health care spending, we believe it is imperative to identify and assist adults with frequent asthma-related ED visits.