title: Clinical COPD Questionnaire in patients with chronic respiratory disease.
abstract: OBJECTIVE
  The Clinical Chronic Obstructive Pulmonary Disease (COPD) Questionnaire (CCQ) is an easy to complete, health-related quality of life questionnaire which has been well-validated in COPD. The responsiveness of the CCQ in chronic respiratory disease patients other than COPD has not been previously described. The study aims were to determine if the CCQ in chronic respiratory disease correlates with other health related quality of life questionnaires, to assess the responsiveness of the CCQ to pulmonary rehabilitation and to determine the minimum important difference.
  
  
  METHODS
  The CCQ, COPD Assessment Test (CAT), the Chronic Respiratory Questionnaire (CRQ) and St George's Respiratory Questionnaire (SGRQ) were measured in 138 chronic respiratory disease patients completing pulmonary rehabilitation. Change in CCQ with pulmonary rehabilitation was correlated with change in the other questionnaires. The minimum important difference of the CCQ was calculated using distribution and anchor-based approaches.
  
  
  RESULTS
  The CCQ, CAT, CRQ and SGRQ improved significantly with rehabilitation with effect sizes of -0.43, -0.26, 0.62, -0.37. Change in CCQ correlated significantly with CAT, CRQ and SGRQ (r = 0.53, -0.64, 0.30, all P < 0.0001). The minimum important difference was -0.42 at the population level and -0.4 at the individual level.
  
  
  CONCLUSIONS
  The CCQ is responsive to pulmonary rehabilitation in chronic respiratory disease patients, with an MID estimated at -0.4 at the individual level.
authors.affiliation: NIHR Respiratory Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust and Imperial College, Middlesex, UK.
authors.forename: Jane L
authors.initials: JL
authors.lastname: Canavan
authors.forename: Deniz
authors.initials: D
authors.lastname: Dilaver
authors.forename: Amy L
authors.initials: AL
authors.lastname: Clark
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Jones
authors.forename: Claire M
authors.initials: CM
authors.lastname: Nolan
authors.forename: Samantha S C
authors.initials: SS
authors.lastname: Kon
authors.forename: William D-C
authors.initials: WD
authors.lastname: Man
mesh_terms: D000368:Aged; D002908:Chronic Disease; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011788:Quality of Life; D012120:Respiration Disorders / Q000150:complications* / Q000503:physiopathology / Q000534:rehabilitation*; D011795:Surveys and Questionnaires
keywords: Clinical Chronic Obstructive Pulmonary Disease Questionnaire; chronic obstructive pulmonary disease; chronic respiratory disease; health-related quality of life; pulmonary rehabilitation