Frequent cough important indicator of adverse outcomes in asthma, COPD

Frequent productive cough is an important indicator of adverse outcomes in individuals with asthma and/or COPD, according to results of the NOVELTY study published in Respiratory Medicine.

“Until recently, chronic cough and sputum production have been mainly associated with COPD,” Rod Hughes, MD, senior medical science director in Research and Early Development in Respiratory and Immunology at AstraZeneca in Cambridge, U.K., and colleagues wrote. “Less is known about the characteristics of patients with asthma with these symptoms.”

Researchers conducted NOVELTY, a global, 3-year prospective observational study that included 7,125 patients in 18 countries with a diagnosis or suspected asthma and/or COPD. Frequent productive cough was defined as cough and sputum production most or several days per week for the past 3 months. Researchers evaluated relationships with baseline disease characteristics and exacerbations during 1-year follow-up.

Almost 53% of patients had asthma, 12.4% had asthma and COPD, 34.9% had COPD and 31.3% had frequent productive cough.

Frequent productive cough was most common among patients with asthma and COPD (38.8%) and among patients with COPD only (38.1%) compared with patients with asthma only (25%). Frequent productive cough increased based on physician-assessed disease severity and also in current smokers compared with former and never smokers.

In patients with frequent productive cough, self-reported symptomatic worsening was more common compared with patients without cough.

Both reduced post-bronchodilator FEV₁ (OR per 10% decrement = 1.14; 95% CI, 1.11-1.16) and pollutant exposure at home/work history (OR = 1.5; 95% CI, 1.33-1.69) were associated with frequent productive cough among patients with any of the three diagnoses.

Patients with frequent productive cough at baseline had a higher likelihood of one or more exacerbation over the subsequent year, including exacerbations leading to hospitalization and those requiring treatment with oral corticosteroids (OR = 1.71; 95% CI, 1.52-1.93).

“Further research is required to understand the different pathobiologies underlying frequent productive cough and support the development of targeted therapies that improve patient outcomes rather than conventional treatment strategies based on either diagnostic label or clinical trait alone,” the researchers wrote. “Clinical trials investigating frequent productive cough should be designed to include broader populations to ensure that new therapies effectively target this trait.”