Prior Asthma Exacerbations Predict Future Severe Exacerbations

As the third most common cause of readmission among Medicare beneficiaries, chronic obstructive pulmonary disease (COPD) manifests in about 60% of patients within 1 year of hospital discharge and in 30% within 3 months of discharge.

Asthma exacerbations often plague individuals with severe asthma as they deteriorate their quality of life and lead to mounting asthma-related costs. Since patients face such challenging circumstances, a team of investigators sought to evaluate potential predictors of a future exacerbation using the long-term observational data from the TENOR II study.

Among the results, the team found that a prior asthma exacerbation was associated with a 2.5-fold increase in the odds of a future severe exacerbation (FSE). In addition, they found patients with an FSE were more likely to be female, have a history of chronic obstructive pulmonary disease (COPD), lower lung function, and use combined inhaled corticosteroid (ICS)/long-acting β2-agonist (LABA) medication and systemic corticosteroids.

“Identifying patients at the greatest risk for future severe exacerbations is crucial for developing effective prevention strategies, reducing health care costs, and achieving the goals of asthma management,” the study authors wrote. “Previous studies have shown that a prior asthma exacerbation is a strong predictor of a future exacerbation in patients with severe or difficult-to-treat asthma.”

According to estimates from The Global Initiative for Asthma (GINA), approximately 17% of asthma patients are considered difficult-to-treat, meaning the patients’ asthma is uncontrolled despite treatment with a medium- or high-dose inhaled corticosteroid or with a second controller and maintenance oral corticosteroid therapy; or they require treatment to maintain good symptom control and reduce the risk of exacerbations.

Additionally, GINA indicates an estimated 3.7% of asthma patients are considered severe in that asthma is uncontrolled despite adherence with maximal optimized therapy and treatment of contributory factors, or worsens when high dose treatment is decreased.

The TENOR I was a prospective observational study that evaluated patients with severe or difficult-to-treat asthma. The TENOR II study—a multicenter, observational study with a cross-sectional single follow-up assessment of patients with severe or difficult-to-treat asthma—evaluated the natural history and long-term outcomes in this cohort more than 10 years following the TENOR I study.

The TENOR II analysis included a decade of data from The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR I) and TENOR II observational studies.

According to the American Thoracic Society, an FSE was defined as a hospitalization or emergency department visit due to asthma that required systemic corticosteroids7 within the 3 months before TENOR II baseline.

By using TENOR II variables, with the exception of a prior severe exacerbation from TENOR I, multivariable logistic regression was used to evaluate the predictors of an ATS-defined severe exacerbation at TENOR II.

According to the results, a total of 288 patients were included in this analysis; n=67 (23.3%) of these patients experienced an FSE.

In addition to the distribution of race/ethnicity, the mean ± SD age (in years) of patients with an FSE and those with no FSE were similar (59.9 ± 12.5 vs. 57.9 ± 16.9, respectively). Between the 2 groups, similarities also stood out in total immunoglobulin E (IgE) levels, eosinophil levels (cells/μL), and fractional exhaled nitric oxide (FeNO, ppb) levels.

Furthermore, “Patients with an FSE were more likely to be female, to have a history of chronic obstructive pulmonary disease (COPD), lower lung function, and were more likely to use combined inhaled corticosteroid (ICS)/long-acting β2-agonist (LABA) medication and systemic corticosteroids compared to patients with no FSE.”

From the results, the team concluded that a prior asthma exacerbation is associated with a 2.5-fold increase in the odds of a future severe exacerbation, which are consistent with previously reported findings that show higher levels of medication use in combination with lower lung function are associated with a future asthma exacerbation.

“Our findings indicate that a prior asthma exacerbation remains a predictor of a future exacerbation in patients with severe or difficult-to-treat asthma even after a decade,” the authors wrote. “Improved treatment strategies to prevent asthma exacerbations and preserve lung function are needed to ameliorate long-term outcomes in patients with severe or difficult-to-treat asthma.”

The study, “Predictors of a Future Severe Asthma exacerbation after a Decade Follow-Up: Results form TENOR II," were presented in a poster presentation at the American College of Allergy, Asthma and Immunology Annual Scientific Meeting, November 15-19, 2018, Seattle, Washington.