Methylxanthine use for acute asthma in the emergency department in Japan: a multicenter observational study

Aim Methylxanthines are no longer recommended for emergency department (ED) patients with acute asthma according to international guidelines. We aimed to describe the current methylxanthine use for acute asthma and to determine factors related to its use in the ED. Methods We undertook a multicenter retrospective study in 23 EDs across Japan. From each participating hospital, we randomly identified 60 ED patients aged 18-54 years with acute asthma from 2009 through 2011. We examined the associations of ED and patient characteristics with methylxanthine use by constructing a multivariable logistic regression model adjusting for a predefined set of ED- and patient-level factors. Results Among 1,380 patients, methylxanthines were used for 79 patients (5.7%, 95% confidence interval [CI], 4.6-7.0%). The proportion of methylxanthine treatment varied substantially among EDs, ranging from 0% to 26.1%. In the multivariable analysis, the number of annual ED patients with acute asthma (odds ratio [OR] per 100 increase in annual asthma patients, 0.12; 95% CI, 0.04-0.34; P < 0.001) and having a protocol for asthma treatment (OR 2.91; 95% CI, 1.06-8.00; P = 0.04) at the ED level, and systemic corticosteroid use (OR 6.39; 95% CI, 3.34-12.22; P < 0.001) at the patient level were associated with likelihood of methylxanthine use. Conclusions In this multicenter study, approximately 6% of ED patients with acute asthma were treated with methylxanthines, with a wide variation across EDs. The number of annual ED patients with acute asthma was significantly associated with a lower likelihood of methylxanthine use, whereas having an ED asthma treatment protocol and systemic corticosteroid use in the ED were associated with a higher likelihood of methylxanthine treatment.