Participant history and symptoms
exertional breathlessness, exhaled carbon monoxide, cough, bronchitis, dyspnoea, wheeze
RESPIRATORY DISEASE, BRONCHITIS
At the LHC, participants were asked about a history of respiratory disease, presence of respiratory symptoms (exertional breathlessness, chronic cough, regular sputum production, wheeze, frequent winter bronchitis), number of hospital admissions for chest problems, number of antibiotic courses in the last 12 months, modified Medical Research Council (mMRC) dyspnoea score (0–4), and WHO performance status (0–4). Smoking status was recorded and number of pack years calculated. Participants had exhaled carbon monoxide measured and performed routine spirometry up to the onset of the COVID-19 pandemic in March 2020; spirometry did not continue following recommencement of screening in July 2020.