Mustafaa Wahab, Elena Kum, Nermin Diab, Danica Brister, Ana Oliveira, Wafa Hassan, Sue Beaudin, Catie Stevens, Jennifer Wattie, Lesley Wiltshire, Karen Howie, Kieran Killian, Kimberley Holt, Gordon Guyatt, Roma Sehmi, Gail M Gauvreau, Jaclyn A Smith, Paul M O'Byrne, Imran Satia
Guideline-based therapy improves objective and subjective cough outcomes; however, most patients fail to achieve satisfactory symptom control, highlighting a substantial unmet need for effective treatments for refractory unexplained chronic cough.
AIM: Chronic cough is a common and burdensome condition with limited licensed therapies. Current guidelines recommend identifying treatable traits and using off-label therapies based largely on small clinical trials, but the real-world effectiveness of this approach remains unclear. This study aimed to evaluate the effectiveness of guideline-based therapies on objective and patient-reported outcomes in patients with chronic cough attending a tertiary cough clinic.
METHODS: PROCOUGH was a prospective, single-centre, observational cohort study conducted at McMaster University Medical Centre (December 2021 to May 2025). Adults with chronic cough (>8 weeks) underwent comprehensive assessment, including lung function testing, airway inflammation measures, sputum cytology and 24-h cough monitoring (VitaloJAK™), alongside patient-reported outcomes. Patients were treated according to European Respiratory Society guideline recommendations, with all assessments repeated after a treatment trial. The primary outcome was change in 24-h cough frequency. Secondary outcomes included Leicester Cough Questionnaire (LCQ) and Cough severity visual analogue scale (CS-VAS). Responder analyses were based on ≥30% cough frequency reduction, ≥30 mm CS-VAS improvement and ≥1.3-point LCQ increase.
RESULTS: 100 patients completed follow-up (mean±sd age 58.1±14.0 years; 58% female; median cough duration 7 years). Treatment resulted in a 54% reduction in 24-h cough frequency (95% CI 42.0-62.9%), a 20.2-mm decrease in CS-VAS (95% CI -26.2- -14.2) and a 3.4-point increase in LCQ (95% CI 2.6-4.2). Individually, 56%, 36% and 64% met cough frequency, CS-VAS and LCQ responder criteria, respectively, but only 14% met all three. Despite treatment, 71% reported insufficient cough control.
CONCLUSION: Guideline-based therapy improves objective and subjective cough outcomes; however, most patients fail to achieve satisfactory symptom control, highlighting a substantial unmet need for effective treatments for refractory unexplained chronic cough.