Comparing Ran-Out Status of Inhaled Short-Acting Beta-Agonists in Emergency Department Patients with Acute Asthma: 1996-1998 versus 2015-2017.

Background: Medication nonadherence, including running out of inhaled asthma medications, is an important problem.

Objective: The objective of this study was to examine the changes in the proportion of adults with acute asthma who ran out of their short-acting beta-agonist (SABA) inhalers before presenting to the emergency department (ED) between 1996--1998 and 2015-2017.

Methods: We analyzed data from prospective multicenter observational cohort studies of ED adult patients (aged 18-54 years) with acute asthma. Within the same 3 EDs, we performed a structured interview during 2 time periods: 1996-1998 and 2015-2017. We fitted multivariable models to compare ran-out status between the 2 periods, adjusting for the baseline patient demographics, socioeconomic status, chronic asthma factors, and health care utilization factors. We further adjusted for the presence of a written action plan-an intervenable factor.

Results: The analytic cohort comprised 353 patients (150 from the 1996-1998 studies and 203 from the 2015-2017 study). Over the approximately 20-year period, the proportion of patients who ran out of SABA inhalers increased (18% in 1996-1998 vs 26% in 2015-2017). In the multivariable model, compared with patients in 1996-1998, those in 2015-2017 had a significantly higher risk of running out of their SABA inhalers (adjusted odds ratio [OR] 2.01; 95% confidence interval [CI] 1.06-3.81; P = .03). With further adjustment for the presence of a written action plan, this difference attenuated (adjusted OR 1.66; 95% CI 0.75-3.68; P = .21).

Conclusions: Between 1996 and 2017, the proportion of ED patients with asthma who ran out of SABA inhalers significantly increased. The increase was explained, at least partially, by a lack of a written action plan.