Frequent productive cough associated with worse outcomes in asthma, COPD
According to the results of a recent study, frequent productive cough was experienced by patients with asthma and/or chronic obstructive pulmonary disease (COPD), with the prevalence of symptoms increasing with disease severity.
Frequent productive cough was present in patients with asthma and/or chronic obstructive pulmonary disease (COPD) at all physician-assigned severity levels. According to the results of a study published in respiratory medicine, the prevalence of frequent productive cough increased with disease severity, was associated with a significant disease burden, and presented as an indicator of an increased risk of adverse disease outcomes.
This study included patients with asthma and/or COPD who participated in the NOVELTY study, a 3-year prospective global observational study that includes approximately 12,000 patients with asthma and/or COPD from clinical practices. clinics in 18 countries. The patients were divided into groups according to the diagnosis – asthma, COPD or asthma and COPD – and the severity assessed by the doctor: mild, moderate or severe. The total cohort included 7125 patients: 3754 (52.7%) had asthma, 887 (12.4%) had asthma and COPD, and 2484 (34.9%) had COPD.
The researchers defined frequent productive cough using 2 questions from the St George’s Respiratory Questionnaire (SGRQ): “In the past 3 months, I have coughed…” and “In the past 3 months, I have passed phlegm (sputum)…” Responses ranged from 0 to 4, with 4 indicating more frequent coughing or phlegm. Patients were defined as having frequent productive cough if they scored 3 or more on both items, meaning they had cough and phlegm on most or several days of the week during of the last 3 months.
Patients who scored 3 or more for only one of the SGRQ questions were defined as having frequent coughing or frequent sputum production. A score of 3 or more on the SGRQ cough question and a score of 1 or less on the SGRQ sputum production question were defined as having a frequent dry (nonproductive) cough.
Patient data from baseline and one-year follow-up clinical study visits were assessed using logistic regression. These data included physician-assigned diagnosis, physician-assessed severity, comorbidities, medications, biomarkers, spirometry, exacerbations, patient-reported questionnaires, and exposure history (pollutant exposure).
Frequent productive cough was present in 31.3% of patients, frequent cough was present in 46.0%, and frequent sputum production was present in 40.4%. A frequent dry cough was found in 8.1%, and a frequent cough or frequent production of sputum was found in 55.2%.
Frequent productive cough was more common in patients with both asthma and COPD (38.8%). Comparing patients with only COPD or only asthma, frequent productive cough was more common in patients with COPD (38.1%) than in patients with asthma (25.0%). This trend was also observed for frequent coughing and frequent sputum production.
The proportion of patients with frequent coughing and/or sputum production increased as physician-assessed severity worsened. Frequent productive cough was also more common in current smokers (48.5%) than in former smokers (30.6%) and never smokers (24.6%) and in non-smokers with COPD (40. 9%) than in non-smokers with asthma (23.0%) .
Patients with frequent productive cough reported greater symptomatic worsening than patients without frequent productive cough, and their condition was associated with exposure to pollutants at home or at work and reduced post-bronchodilator forced expiratory volume. in 1 sec. Additionally, patients with a reported frequent productive cough at baseline were more likely than those without to have 1 or more exacerbations over the following year. These exacerbations included those resulting in hospitalization or requiring treatment with oral corticosteroids.
There were some limitations to this study. Comparisons between diagnostic groups may have been hampered by differences in patient age, as frequent symptoms of productive cough increase with age. Additionally, the study did not include imaging data, and the researchers were unable to analyze the patients’ sputum.
“Frequent productive cough represents an important indicator of adverse clinical outcomes in asthma and/or COPD,” the researchers concluded. “Research into the underlying disease mechanisms is needed to support the development of targeted therapies.”
Hughes R, Rapsomaniki E, Janson C, et al; NOVELTY study investigators Frequent productive cough: symptom burden and risk of future exacerbation in patients with asthma and/or COPD in the NOVELTY study. Breath Med. Published online June 20, 2022. doi:10.1016/j.rmed.2022.106921