Registry Study Shows Severe Asthma Demographics

David B. Price, MD

A first-of-its-kind cohort trial assessing the characteristics of patients with severe asthma found a majority of registry-based patients are white, female, obese, and non-smokers.

The findings, which are based off registry data of nearly 5000 patients aged 18 years or older from various international countries and the US, provide new context to the overall burden of severe asthma per patient demographics.

Led by David B. Price, MD, chair of Primary Care Respiratory Medicine at the Institute of Applied Health Sciences, University of Aberdeen, a team of international investigators sought to describe a combination of demographic and clinical characteristics of patients to have had severe asthma managed in services from areas in the US, Europe, and the Asia/Pacific region. As they noted, such details of the patient population are unknown, and difficult to comprehensively track.

“Inter-country comparisons are hindered by variable data collection within regional/national severe asthma registries,” investigators wrote.

Price and colleagues retrospectively collected data from the International Severe Asthma Registry (ISAR), which included 4990 adult patients with severe asthma receiving Global Initiative for Asthma (GINA) Step 5 therapy, or remaining uncontrolled on GINA Step 4. The registry includes US, United Kingdom, South Korea, Italy, and SAWD patients.

The team collected baseline data on patient demographics and their clinical data from December 2014-December 2017. Mean patient age was 55 years, with asthma onset at 30.7 years.

Nearly 60% were female (59.3%), most (72.6%) were white, and three-fifths (60.5%) had never smoked. Another 70.4% were overweight or obese.

Though 34.9% of patients were on GINA Step 5, most (57.2%) patients had poorly controlled disease. Another 51.1% of patients were on regular intermittent oral corticosteroids, and one-quarter (25.4%) were on biologics. Among patients on GINA Step 5, 72.6% were on biologic therapy.

Mean patient exacerbation rate was 1.7 annually. Clinical characteristics, prescribed treatments, and biomarker profiles varied by country.

Real-world, global assessments into the clinical characteristics and patient demographics of severe asthma are still a burgeoning plane of research. A recent study presented at the CHEST 2019 Annual Meeting in New Orleans this October show 71% of patients with severe asthma from the CHRONICLE study were on biologics. Another 13% were on maintenance corticosteroids, and 18% were on high-dosage corticosteroid with added controllers.

The study also showed physicians were far more likely to overestimate severe asthma control in their patients, when compared to scores from the online patient-completed Asthma Control Test (ACT).

Though previous assessments have evidenced this finding, the CHRONICLE assessment also indicated that patient self-report of asthma control is more closely aligned—yet still an overestimation of control.

Adding to this interpretation of severe asthma management, Price and colleagues concluded their international cohort was the first identify country-by-country differences in patient characteristics using common descriptors.

For more particular data and definitions, further research may be necessary.

“Whether these are related to underlying epidemiological, environmental factors, phenotype, asthma management systems, treatment access and/or cultural factors requires further study,” investigators wrote.

The study, “Characterization of severe asthma worldwide: data from the International Severe Asthma Registry (ISAR),” was published online in CHEST Journal.