Sex differences among adults presenting to the emergency department with acute asthma. Multicenter Asthma Research Collaboration Investigators.

BACKGROUND: Asthma is an increasing problem worldwide, particularly among women. Sex differences in acute asthma presentation, management, or outcome would have important medical and economic implications. OBJECTIVE: To compare emergency department (ED) visits for acute asthma among women vs men. METHODS: We performed a prospective cohort study as part of the Multicenter Asthma Research Collaboration. Patients in the ED, aged 18 to 54 years, who presented with acute asthma underwent a structured interview in the ED and another by telephone 2 weeks later. The study was performed at 36 EDs in 18 states. Pregnant women with asthma were excluded (n=53). RESULTS: Of 1228 patients, 64.3% were women. Women did not differ significantly from men by age or education level, but women were more likely to be insured, have a primary care provider, and use inhaled corticosteroids. Women had a higher mean+/-SD peak expiratory flow rate than men, both early (expressed as percent predicted) (53%+/-21% vs 41%+/-18%; P<.001) and late (77%+/-24% vs 65%+/-21%; P<.001) in the ED stay. Despite this, women were more likely to be admitted to a hospital (multivariate odds ratio, 2.2; 95% confidence interval; 1.3-4.0) than men. At 2-week follow-up, women had not experienced more relapse events (odds ratio, 1.1) but were 1.5 times more likely to report an ongoing exacerbation (95% confidence interval; 1.0-2.4). CONCLUSIONS: Of adults who presented to the ED with acute asthma, women were almost twice as common as men. Although men received less outpatient care and had worse pulmonary function, women were more likely to be admitted to the hospital and to report an ongoing exacerbation at follow-up. Further studies are needed to better understand the complex relationship between sex and acute asthma.