Number of Patient-Reported Severe Asthma Triggers Predicts Morbidity

The number of patient-reported triggers among US patients with severe asthma (SA) is a stronger predictor of disease morbidity than blood eosinophil counts, according to results of research presented at the American College of Allergy, Asthma & Immunology (ACAAI) Annual Scientific Meeting, held from November 10 to 14, in Louisville, Kentucky.

Researchers sought to explore the relationship between the number of self-reported triggers among patients with severe asthma and disease control. They also compared the predictive value of self-reported triggers vs blood eosinophil counts (BEC).

The investigators conducted an analysis of data from the CHRONICLE trial (ClinicalTrials.gov Identifier: NCT03373045), an observational study that enrolled 2847 adult patients with severe asthma receiving maintenance systemic corticosteroids (SCS), biologics, or uncontrolled on high-dosage inhaled corticosteroids and additional controllers between February 2018 to February 2021. The investigators used the Asthma Control Test (ACT), work productivity,  health care professional (HCP)-reported exacerbations, and the Saint George’s Respiratory Questionnaire (SGRQ) to measure disease control and analyze associations with patient-reported triggers (from a 17-category survey).

A total of 1434 (51.3%) patients completed the triggers questionnaire. The most common triggers cited were viral infections, seasonal allergies, weather/air changes, perennial allergies, and exercise. The median trigger number per patient was 8 (IQR 5-10).

Compared to those with 1-3 asthma triggers, patients with higher numbers of triggers also experienced a higher level of uncontrolled asthma (as measured by the ACT and by SGRQ mean score) and a higher level of health care provider-reported exacerbations. Work productivity was affected especially strongly by the number of patient-reported triggers; compared with patients reporting 1-3 triggers, work impairment due to asthma was 3.6 times higher for patients reporting 14-17 triggers, 2.2 times higher for patients reporting 10-13 triggers, and 1.7 times for patients reporting 7-9 triggers.

Further analyses confirmed that patients reporting more triggers experienced worse quality of life, reduced work productivity, more exacerbations, and more poorly controlled disease.

Additionally, the researchers found that the number of triggers was a better predictor of all measures studied than BEC. Notably, the analysis found a higher area under the curve-receiver operating characteristic for trigger numbers than BEC for the prediction of at least 1 exacerbation (0.60 vs 0.53, respectively) as well as for the prediction of at least 1 asthma hospitalization (0.67 vs 0.51, respectively).

Study limitations include the possibility of nonresponse bias.

“Among US specialist-treated patients with SA, number of patient-reported triggers was a better predictor than BEC of disease morbidity across multiple measures,” the researchers concluded.