Sputum clearance devices to improve symptoms in chronic obstructive pulmonary disease

INTERVENTION: Participants will be randomised to OPEP device (the AcapellaTM) with usual care or usual care alone. Allocation will be by computer‐generated list. Active: Taught active cycle of breathing. Acapella device used at least three times per day Control: Taught active cycle of breathing The Acapella group will receive teaching on how to use the device then take it home (asked to use it at least three times daily). Both groups will have measures of quality of life (the main research outcome) and severity of cough symptoms compared using well‐established questionnaires at the beginning and after 3 months. A subset of patients will also wear a cough monitor and an activity monitor for 3 days. CONDITION: COPD patients who produce sputum regularly ; Respiratory PRIMARY OUTCOME: Cough symptoms measured using the Leicester cough questionnaire (LCQ) at baseline and 12 weeks SECONDARY OUTCOME: ; 1. Cough severity measured by Visual Analog Scale (VAS) at baseline and 12 weeks; 2. Health status measured by CAT score at baseline and 12 weeks; 3. Health status measured using EQ‐5D‐5L at baseline and 12 weeks; 4. Fatigue measured using FACIT score at baseline and 12 weeks; 5. Exacerbation rate (number of exacerbations during the 12 weeks of the study) measured using patient diaries at 12 weeks; ; A subset of 32 participants will undergo measurement of cough frequency and sleep movements to determine whether the OPEP device influences cough frequency and sleep efficiency. This will use the Leicester Cough Monitor and the McRoberts MoveMonitor at baseline and 12 weeks; INCLUSION CRITERIA: 1. Adult patients with COPD who frequently produce sputum defined as: (i) every or most days in the last month and a score of >=6/8 on the two CAT cough items 2. Stable treatment for the preceding four weeks