title: Comparison of the COPD Assessment Test (CAT) and the Clinical COPD Questionnaire (CCQ) in a Clinical Population.
abstract: BACKGROUND
  The COPD Assessment Test (CAT) and the Clinical COPD Questionnaire (CCQ) are both clinically useful health status instruments. The main objective was to compare CAT and CCQ measurement instruments.
  
  
  METHODS
  CAT and CCQ forms were completed by 432 randomly selected primary and secondary care patients with a COPD diagnosis. Correlation and linear regression analyses of CAT and CCQ were performed. Standardised scores were created for the CAT and CCQ scores, and separate multiple linear regression analyses for CAT and CCQ examined associations with sex, age (≤ 60, 61-70 and >70 years), exacerbations (≥ 1 vs 0 in the previous year), body mass index (BMI), heart disease, anxiety/depression and lung function (subgroup with n = 246).
  
  
  RESULTS
  CAT and CCQ correlated well (r = 0.88, p < 0.0001), as did CAT ≥ 10 and CCQ ≥ 1 (r = 0.78, p < 0.0001). CCQ 1.0 corresponded to CAT 9.93 and CAT 10 to CCQ 1.29. Both instruments were associated with BMI < 20 (standardised adjusted regression coefficient (95%CI) for CAT 0.56 (0.18 to 0.93) and CCQ 0.56 (0.20 to 0.92)), exacerbations (CAT 0.77 (0.58 to 0.95) and CCQ 0.94 (0.76 to 1.12)), heart disease (CAT 0.38 (0.17 to 0.59) and CCQ 0.23 (0.03 to 0.43)), anxiety/depression (CAT 0.35 (0.15 to 0.56) and CCQ 0.41 (0.21 to 0.60)) and COPD stage (CAT 0.19 (0.05 to 0.34) and CCQ 0.22 (0.07 to 0.36)).
  
  
  CONCLUSIONS
  CAT and CCQ correlate well with each other. Heart disease, anxiety/depression, underweight, exacerbations, and low lung function are associated with worse health status assessed by both instruments.
authors.affiliation: a Department of Respiratory Medicine, Örebro University , Örebro , Sweden.
authors.forename: Josefin
authors.initials: J
authors.lastname: Sundh
authors.affiliation: b Department of Public Health and Caring Science, Family Medicine and Preventive Medicine, Uppsala University , Uppsala , Sweden.
authors.forename: Björn
authors.initials: B
authors.lastname: Ställberg
authors.affiliation: b Department of Public Health and Caring Science, Family Medicine and Preventive Medicine, Uppsala University , Uppsala , Sweden.
authors.forename: Karin
authors.initials: K
authors.lastname: Lisspers
authors.affiliation: c Department of Medical Sciences, Respiratory Medicine and Allergology, Uppsala University , Uppsala , Sweden.
authors.forename: Mary
authors.initials: M
authors.lastname: Kämpe
authors.affiliation: c Department of Medical Sciences, Respiratory Medicine and Allergology, Uppsala University , Uppsala , Sweden.
authors.forename: Christer
authors.initials: C
authors.lastname: Janson
authors.forename: Scott
authors.initials: S
authors.lastname: Montgomery
mesh_terms: D000367:Age Factors; D000368:Aged; D001007:Anxiety / Q000523:psychology; D015992:Body Mass Index; D015331:Cohort Studies; D003863:Depression / Q000523:psychology; D018450:Disease Progression; D005260:Female; D005541:Forced Expiratory Volume; D006304:Health Status; D006331:Heart Diseases / Q000150:complications; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000503:physiopathology* / Q000523:psychology; D012720:Severity of Illness Index; D012737:Sex Factors; D011795:Surveys and Questionnaires; D013851:Thinness / Q000150:complications
keywords: CAT; CCQ; COPD; anxiety; depression; exacerbations; health status; heart disease; underweight