The cutoff point of clinical chronic obstructive pulmonary disease questionnaire for more symptomatic patients

An adequate threshold for the Clinical Chronic Obstructive Pulmonary Disease (COPD) Questionnaire (CCQ) defining more symptomatic COPD patients has not been determined. We aimed to determine the efficacy of the CCQ and the appropriate CCQ threshold for more symptomatic COPD patients. COPD patients aged > 40 years who smoked/had smoked ≥10 packs/year were prospectively enrolled over 1 year from three South Korean hospitals (n = 126). Correlations...