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The COPD assessment test (CAT): response to pulmonary rehabilitation. A multicentre, prospective study
  1. James W Dodd1,
  2. Lauren Hogg2,
  3. Jane Nolan1,
  4. Helen Jefford3,
  5. Amy Grant4,
  6. Victoria M Lord5,
  7. Christine Falzon6,
  8. Rachel Garrod7,
  9. Cassandra Lee8,
  10. Michael I Polkey5,
  11. Paul W Jones1,
  12. William D-C Man5,
  13. Nicholas S Hopkinson5
  1. 1St George's Hospital NHS Trust, London, UK
  2. 2Guy's and St Thomas' Foundation NHS Trust, London, UK
  3. 3Greenwich Primary Care Trust, London, UK
  4. 4Croydon Primary Care Trust, London, UK
  5. 5The NIHR Respiratory Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust and Imperial College, London UK
  6. 6Central London Community Healthcare, London, UK
  7. 7King's College Hospital NHS Foundation Trust, London, UK
  8. 8Imperial College Healthcare NHS Trust, UK
  1. Correspondence to Nicholas Hopkinson, The NIHR Respiratory Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust and Imperial College, Royal Brompton Hospital, Fulham Rd, London SW3 6NP, UK; n.hopkinson{at}


Background The COPD (chronic obstructive pulmonary disease) assessment test (CAT) is a recently introduced, simple to use patient-completed quality of life instrument that contains eight questions covering the impact of symptoms in COPD. It is not known how the CAT score performs in the context of clinical pulmonary rehabilitation (PR) programmes or what the minimum clinically important difference is.

Methods The introduction of the CAT score as an outcome measure was prospectively studied by PR programmes across London. It was used alongside other measures including the St George's Respiratory Questionnaire, the Chronic Respiratory Disease Questionnaire, the Clinical COPD Questionnaire, the Hospital Anxiety and Depression score, the Medical Research Council (MRC) dyspnoea score and a range of different walking tests. Patients completed a 5-point anchor question used to assess overall response to PR from ‘I feel much better’ to ‘I feel much worse’.

Results Data were available for 261 patients with COPD participating in seven programmes: mean (SD) age 69.0 (9.0) years, forced expiratory volume in 1 s (FEV1) 51.1 (18.7) % predicted, MRC score 3.2 (1.0). Mean change in CAT score after PR was 2.9 (5.6) points, improving by 3.8 (6.1) points in those scoring ‘much better’ (n=162), and by 1.3(4.5) in those who felt ‘a little better’ (n=88) (p=0.002). Only eight individuals reported no difference after PR and three reported feeling ‘a little worse’, so comparison with these smaller groups was not possible.

Conclusion The CAT score is simple to implement as an outcome measure, it improves in response to PR and can distinguish categories of response.

  • Quality of life
  • minimal clinically important difference
  • COPD
  • pulmonary rehabilitation

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  • Funding The National Institute of Health Research (NIHR) Respiratory Biomedical Research Unit Royal Brompton & Harefield NHS Foundation Trust and Imperial College. WD-CM is funded by an NIHR Clinician Scientist award. The views expressed in this publication are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health. NSH is an HEFCE Clinical Senior Lecturer.

  • Competing interests None.

  • Ethics approval This study was conducted with the approval of the Riverside Research Ethics Committee.

  • Provenance and peer review Not commissioned; externally peer reviewed.