A 10-year follow-up of patients with severe asthma finds persistent illness remains difficult to treat.
Ten years after the largest study of patients with severe asthma documented long-standing morbidity and reduced lung function, over half of patients continue to have poorly controlled asthma despite treatment, and many have conditions suggesting irreversible lung disease.
"This relates to a persistent high burden of illness," Bradley Chipps, MD (pictured), president-elect of the American College of Allergy and the Asthma & Immunology and medical director at the Capital Allergy & Respiratory Disease Center, in Sacramento, told MD Magazine. "We found a very high frequency of uncontrolled asthma, 58%, with a 72 % FEV1 (forced expiratory volume in 1 second, after bronchodilator treatment), and multiple co-morbidities.”
In addition to the challenges in treating a severe illness emerging from heterogeneous conditions and comprising multiple phenotypes, Chipps and colleagues found that suboptimal medication use contributed to poor outcomes. He and colleagues wrote that "study findings suggest under treatment in this cohort of severe or difficult-to-treat asthma, which suggests that clinicians may not be adhering to asthma guidelines and adjusting therapy as appropriate."
It resulted in a "gross underutilization of biologics and under treatment with standard medication," Chipps said.
The follow-up study, TENOR II, was conducted in a single visit during 2013/2014 at 59 of the 283 sites which had participated 10 years earlier in the 3-year long assessment of patients with severe asthma, TENOR I (The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens).
TENOR I had enrolled 4756 patients: 770 children, 497 adolescents, and 3489 adults, while TENOR II recruited 341 patients with a mean age of 57.8 years (SD 16.3 years). At the time of their enrollment in TENOR I, 308 of these patients had been adults (≥18 years), 15 had been adolescents (12-17 years) and 18 had been children (6-11 years).
Variables collected in TENOR II encompassed those of TENOR I, including demographics, comorbid conditions, asthma-related medication use and self-reported health care utilization. In addition, TENOR II gathered data on sun exposure, asthma triggers such as air pollution and non-tobacco smoke, and use of additional allergy and asthma medications including approved and experimental biologics.
Lab assessments included total serum IgE level. Spirometry and fractional exhaled nitric oxide measurements were taken, with lung function measured by pre-and post-bronchodilator FEV1 and forced vital capacity (FVC). Patients were categorized by level of asthma control, from very poorly controlled, to not well controlled, to well controlled, based on the impairment domain of the NHLBI/National Asthma Education and Prevention Program (NAEPP) Expert Panel Review (EPR)-3 guidelines.
Chipps and colleagues reported finding over half of the patients (58.1%) having very poorly controlled asthma, and 34.2% had not well-controlled asthma. Only a small proportion (7.7%) were found to have well-controlled asthma. An asthma exacerbation in the 3 months prior to the TENOR II study visit was reported by 25.8% of patients. Of these, 21.6% required emergency department or hospital treatment and 89.8% required systemic corticosteroid treatment.
Combined inhaled corticosteroids and long-acting beta2 agonists were being taken by 71% of patients, and 39.6% were taking a leukotrine modifier. Systemic corticosteroids and long-acting anticholinergic/muscarinic antagonists were each used by 11.2%, and 11.8% were taking omalizumab (Xolair, Genentech and Novartis--sponsors of TENOR II).
Chipps and colleagues characterize the patients of TENOR II as having a persistent high rate of very poorly controlled asthma and multiple comorbidities, frequent asthma exacerbations, and a number of barriers to medication adherence.
They indicated their plans to conduct additional analysis of the data to explore longitudinal aspects and predictors of poor control and exacerbation, as well as the influence of atopy on asthma-related outcomes.
The TENOR II report was published online August 8 in the Journal of Allergy and Clinical Immunology.