Fig. 3From: The cutoff point of clinical chronic obstructive pulmonary disease questionnaire for more symptomatic patientsCorrelation between the CCQ and the (a) FEV1% and (b) 6MWD. Abbreviations: CCQ, Clinical Chronic Obstructive Pulmonary Disease Questionnaire; FEV1, forced expiratory volume in 1 s; 6MWT, 6-min walk testBack to article page