Moving Beyond Responders: A Post Hoc Analysis Identifying Criteria for Chronic Cough Control

Area of Science:

• Pulmonology
• Clinical Trials
• Patient-Reported Outcomes

Background:

• Minimally important differences (MIDs) are often used to define treatment response in refractory chronic cough (RCC).
• MIDs represent the smallest change patients perceive as important, not necessarily adequate cough control.
• Defining specific criteria for cough control can offer a complementary benchmark for treatment success.

Purpose of the Study:

• To define cough control using patient-perceived sufficiency thresholds.
• To determine the proportion of patients achieving cough control after treatment.

Main Methods:

• Prospective, single-centre observational cohort study (PROCOUGH).
• Patients received treatment per ERS guidelines with pre- and post-treatment assessments.
• Post-hoc analysis defined cough control criteria using Global Rating of Change Scale (GROC 6-7) and a treatment response question.

Main Results:

• Controlled cough (ConCC) defined by 24-h cough frequency (CF) ≤10/h, Cough Severity VAS (CS-VAS) ≤30 mm, and Leicester Cough Questionnaire (LCQ) ≥16.
• Only 26% of patients met all three ConCC criteria post-treatment; 74% remained RCC.
• Individual criteria were met by higher proportions: LCQ (36%), CS-VAS (44%), and CF (50%).

Conclusions:

• Patient-anchored criteria for cough control were derived, integrating objective (CF) and subjective (CS-VAS, LCQ) outcomes.
• The composite criteria revealed a low achievement rate (26%) for cough control.
• This highlights the need for improved treatments and outcome definitions that reflect patient-perceived cough control.