Factors associated with emergency department visits in asthma exacerbation

Despite quality improvement initiatives to prevent asthma-related emergency department (ED) visits, rates have not declined. We sought to determine factors associated with ED visits in an underserved population.

We performed a case-control analysis of asthma patients at three ambulatory care centers serving low-income populations. Cases consisted of asthmatic patients aged 18 to 45 years with ≥1 ED visit for an asthma exacerbation between August 1, 2008 and July 31, 2010. Controls were patients with asthma aged 18 to 45 years with ≥1 outpatient visit during the same period but with no asthma-related ED visit. Data were collected by chart review and included demographics, past referral for asthma education or to a pulmonologist, recent tobacco use, influenza vaccination, and asthma medication prescriptions in the year before the index visit.

Among 244 cases and 475 controls, there were no significant differences in age, sex, or ethnicity. Cases were more likely than controls to have ever been referred for asthma education (odds ratio [OR] 4.09, 95% confidence interval [CI] 2.57-6.50) or to a pulmonologist (OR 2.31, 95% CI 1.15-4.66). In the year before the index visit, cases were more likely than controls to receive other medications in addition to inhaled corticosteroids (ICS; OR 1.74, 95% CI 1.14-2.66) but less likely to receive influenza vaccination (OR 0.49, 95% CI 0.34-0.71), a short-acting β-agonist (OR 0.43, 95% CI 0.24-0.78), or ICS alone (OR 0.53, 95% CI 0.34-0.84).

Markers of severe disease were associated with ED visits, as well as a lack of an influenza vaccination and failure to prescribe either ICS or short-acting β-agonists.