All-Cause Mortality After Severe Asthma Exacerbation Remains High

In patients with asthma and severe asthma, all-cause mortality associated with a severe exacerbation is highest in the first month after the event, according to study results published in Respiratory Medicine.

Researchers identified a total of 586,436 adult patients with asthma from electronic databases from the United Kingdom, Netherlands, Italy, Denmark, and Spain. Only patients with ≥1 year of follow-up data during the period from 2008 and 2013 were included in this study. In the identified asthma cohort, approximately 7.3% (n=42,611) of patients had severe asthma, defined as the use of high-dose inhaled corticosteroids plus a second controller.

The researchers identified severe asthma exacerbations during each follow-up period. Severe asthma exacerbations were characterized as any asthma event that required an emergency department visit, hospitalization, or systemic corticosteroid use.

At the start of each follow-up period, the mean ages in the overall cohort ranged between 45.2 and 48.3 years. During follow-up, a total of 15,349 deaths were reported. Across all databases, the age- and sex-standardized all-cause mortality rates in patients with asthma were 5.2 per 1000 person-years to 9.5 per 1000 person-years. The age- and sex-standardized all-cause mortality rates in patients with severe asthma ranged between 11.3 per 1000 person-years and 14.8 per 1000 person-years.

After the first week following a severe asthma exacerbation, the all-cause mortality rate ranged between 14.1 per 1000 person-years and 59.9 per 1000 person-years. In the first month following a severe asthma exacerbation, the mortality rates remained high across all databases. Mortality rates decreased after the first month following severe asthma exacerbations.

Patient characteristics associated with a higher risk for mortality after a severe asthma exacerbation event included older age (hazard ratio [HR], 1.11; 95% CI, 1.10-1.11; P <.0001), male sex (HR, 0.78; 95% CI, 0.70-0.86; P <.0001), history of cancer (HR, 1.95; 95% CI, 1.75-2.16; P <.0001), history of cerebrovascular disease (HR, 1.53; 95% CI, 1.39-1.68; P <.0001), history of diabetes (HR, 1.61; 95% CI, 1.33-1.95; P <.0001), and having prior severe asthma exacerbations (P <.0001).

Limitations of the observational study included the reliance on retrospective data from electronic healthcare databases and the variations among datasets in terms of how lifestyle factors were reported.

The researchers concluded that targeted “asthma treatment focusing on the prevention of severe asthma exacerbations might reduce mortality.”

Disclosure: This clinical trial was supported by GlaxoSmithKline. Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.

Reference

Engelkes M, de Ridder MAJ, Svensson E, et al. Multinational cohort study of mortality in patients with asthma and severe asthma [published online March 2, 2020]. Respir Med. doi:10.1016/j.rmed.2020.105919