Article Text

Download PDFPDF
Original article
The Clinical COPD Questionnaire: response to pulmonary rehabilitation and minimal clinically important difference
  1. Samantha S C Kon1,
  2. Deniz Dilaver2,
  3. Manvi Mittal1,
  4. Claire M Nolan1,2,
  5. Amy L Clark2,
  6. Jane L Canavan1,
  7. Sarah E Jones1,
  8. Michael I Polkey1,
  9. William D-C Man1,2
  1. 1NIHR Respiratory Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust and Imperial College, Harefield, UK
  2. 2Harefield Pulmonary Rehabilitation Unit, Royal Brompton & Harefield NHS Foundation Trust, Harefield, UK
  1. Correspondence to Dr Samantha Kon, Department of Respiratory Medicine, Harefield Hospital, Hill End Road, Harefield UB9 6JH, UK; s.kon{at}


Background The Clinical COPD Questionnaire (CCQ) is a simple 10-item, health-related quality of life questionnaire (HRQoL) with good psychometric properties. However, little data exists regarding the responsiveness of the CCQ to pulmonary rehabilitation (PR) or the minimal clinically important difference (MCID). The study aims were to assess the responsiveness of the CCQ to PR, to compare the responsiveness of the CCQ to other HRQoL questionnaires and to provide estimates for the MCID.

Methods The CCQ, St George's Respiratory Questionnaire (SGRQ), Chronic Respiratory Questionnaire (CRQ) and COPD Assessment Test (CAT) were measured in 261 patients with COPD before and after outpatient PR. Pre to post PR changes and Cohen's effect size were calculated. Changes in CCQ were compared with changes in other HRQoL questionnaires. Using an anchor-based approach and receiver operating characteristic (ROC) curves, the CCQ change cutoffs that identified patients achieving the known MCID for other health status questionnaires with PR were identified.

Results The CCQ, SGRQ, CRQ and CAT all significantly improved with PR with an effect size of −0.39, −0.33, 0.62 and −0.25, respectively. CCQ change correlated significantly with change in SGRQ, CRQ and CAT (r=0.48, −0.56, 0.54, respectively; all p<0.001). ROC curves consistently identified a CCQ change cutoff of −0.4 as the best discriminating value to identify the MCID for the SGRQ, CRQ and CAT (area under curve: 0.71, 0.75 and 0.77, respectively; all p<0.001).

Conclusions The CCQ is responsive to PR with an estimated clinically important improvement of −0.4 points. The CCQ is a practical alternative to more time-consuming measures of HRQoL.

  • Pulmonary Rehabilitation
  • COPD Pathology

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.