title: Discrepancies between modified Medical Research Council dyspnea score and COPD assessment test score in patients with COPD.
abstract: OBJECTIVE
  According to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines, either a modified Medical Research Council (mMRC) dyspnea score of ≥2 or a chronic obstructive pulmonary disease (COPD) assessment test (CAT) score of ≥10 is considered to represent COPD patients who are more symptomatic. We aimed to identify the ideal CAT score that exhibits minimal discrepancy with the mMRC score.
  
  
  METHODS
  A receiver operating characteristic curve of the CAT score was generated for an mMRC scores of 1 and 2. A concordance analysis was applied to quantify the association between the frequencies of patients categorized into GOLD groups A-D using symptom cutoff points. A κ-coefficient was calculated.
  
  
  RESULTS
  For an mMRC score of 2, a CAT score of 15 showed the maximum value of Youden's index with a sensitivity and specificity of 0.70 and 0.66, respectively (area under the receiver operating characteristic curve [AUC] 0.74; 95% confidence interval [CI], 0.70-0.77). For an mMRC score of 1, a CAT score of 10 showed the maximum value of Youden's index with a sensitivity and specificity of 0.77 and 0.65, respectively (AUC 0.77; 95% CI, 0.72-0.83). The κ value for concordance was highest between an mMRC score of 1 and a CAT score of 10 (0.66), followed by an mMRC score of 2 and a CAT score of 15 (0.56), an mMRC score of 2 and a CAT score of 10 (0.47), and an mMRC score of 1 and a CAT score of 15 (0.43).
  
  
  CONCLUSIONS
  A CAT score of 10 was most concordant with an mMRC score of 1 when classifying patients with COPD into GOLD groups A-D. However, a discrepancy remains between the CAT and mMRC scoring systems.
authors: Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Seoul St Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors: Chin Kook
authors: CK
authors: Rhee
authors: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Uijeongbu St Mary's Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu, Republic of Korea.
authors: Jin Woo
authors: JW
authors: Kim
authors: Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Hallym University Medical Center, Hallym University College of Medicine, Anyang, Republic of Korea.
authors: Yong Il
authors: YI
authors: Hwang
authors: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, School of Medicine, Ewha Womans University, Seoul, Republic of Korea.
authors: Jin Hwa
authors: JH
authors: Lee
authors: Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Hallym University Medical Center, Hallym University College of Medicine, Anyang, Republic of Korea.
authors: Ki-Suck
authors: KS
authors: Jung
authors: Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Hallym University Chuncheon Sacred Heart Hospital, Hallym University College of Medicine, Chuncheon, Republic of Korea.
authors: Myung Goo
authors: MG
authors: Lee
authors: Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Republic of Korea.
authors: Kwang Ha
authors: KH
authors: Yoo
authors: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, St Paul's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors: Sang Haak
authors: SH
authors: Lee
authors: Regional Center for Respiratory Disease, Yeungnam University Medical Center, Yeungnam University College of Medicine, Daegu, Republic of Korea.
authors: Kyeong-Cheol
authors: KC
authors: Shin
authors: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Yeouido St Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors: Hyoung Kyu
authors: HK
authors: Yoon
mesh_terms: D000368:Aged; D019540:Area Under Curve; D003430:Cross-Sectional Studies; D004417:Dyspnea / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology; D012372:ROC Curve; D015203:Reproducibility of Results; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D012720:Severity of Illness Index; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology; D013147:Spirometry; D011795:Surveys and Questionnaires; D014797:Vital Capacity
keywords: CAT; COPD; concordance; discrepancy; mMRC