title: The COPD assessment test (CAT): response to pulmonary rehabilitation. A multicentre, prospective study.
abstract: 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 (FEV(1)) 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.
  
  
  CONCLUSIONS
  The CAT score is simple to implement as an outcome measure, it improves in response to PR and can distinguish categories of response.
authors.affiliation: St George's Hospital NHS Trust, London, UK.
authors.forename: James W
authors.initials: JW
authors.lastname: Dodd
authors.forename: Lauren
authors.initials: L
authors.lastname: Hogg
authors.forename: Jane
authors.initials: J
authors.lastname: Nolan
authors.forename: Helen
authors.initials: H
authors.lastname: Jefford
authors.forename: Amy
authors.initials: A
authors.lastname: Grant
authors.forename: Victoria M
authors.initials: VM
authors.lastname: Lord
authors.forename: Christine
authors.initials: C
authors.lastname: Falzon
authors.forename: Rachel
authors.initials: R
authors.lastname: Garrod
authors.forename: Cassandra
authors.initials: C
authors.lastname: Lee
authors.forename: Michael I
authors.initials: MI
authors.lastname: Polkey
authors.forename: Paul W
authors.initials: PW
authors.lastname: Jones
authors.forename: William D-C
authors.initials: WD
authors.lastname: Man
authors.forename: Nicholas S
authors.initials: NS
authors.lastname: Hopkinson
mesh_terms: D000368:Aged; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000503:physiopathology / Q000534:rehabilitation*; D011788:Quality of Life; D012720:Severity of Illness Index; D016896:Treatment Outcome