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

• Published in: BMC pulmonary medicine 2018-02, Vol.18 (1), p.38-38, Article 38
• Main Authors: Jo, Yong Suk, Park, Sangshin, Kim, Deog Kyeom, Yoo, Chul-Gyu, Lee, Chang-Hoon
• Format: Article
• Language: English
• Subjects: Aged; Analysis; Chronic Obstructive Pulmonary Disease; Clinical Questionnaires; Correlation study; Development and progression; Female; Forced Expiratory Volume; Health related quality of life; Health Status; Humans; Lung diseases, Obstructive; Male; Middle Aged; Practice guidelines (Medicine); Pulmonary Disease, Chronic Obstructive - diagnosis; Pulmonary Disease, Chronic Obstructive - physiopathology; Quality of Life; Questionnaires; Regression Analysis; Republic of Korea; Retrospective Studies; Risk factors; ROC Curve; Severity of Illness Index; Surveys and Questionnaires
• ISSN: 1471-2466; 1471-2466
• DOI: 10.1186/s12890-018-0601-0

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 between the CCQ and St. George's Respiratory Questionnaire (SGRQ), COPD Assessment Test (CAT), the modified Medical Round Council (mMRC) scale, lung function, and exercise capacity were evaluated. "More symptomatic patients" were those with an SGRQ score ≥ 25. Area under the receiver operating curve and classification and regression tree analyses were performed to determine the CCQ threshold equivalent to an SGRQ score ≥ 25. The CCQ significantly correlated with the SGRQ, CAT, and mMRC scale (r = 0.76, 0.69, and 0.53, respectively). A CCQ cutoff of 1.4 predicted an SGRQ score of 25 better than others. A CCQ score of 1.4 was a significant determinant of an SGRQ score ≥ 25 even after adjusting for potential confounders. The CCQ was correlated with other symptom indicators, lung function, and exercise capacity. A CCQ cutoff of 1.4 agreed better than CCQ cutoff of 1.0, suggested by guideline, and this cutoff value may identify more symptomatic COPD patients well. ClinicalTrials.gov Identifier: NCT02527486 . Date of registration: December 19, 2014, retrospectively registered.