title: Validity, reliability, and responsiveness of the Kansas City Cardiomyopathy Questionnaire in anemic heart failure patients.
abstract: BACKGROUND
  While generic health status measures quantify the impact of all patients' diseases on their health-related quality of life, disease specific measures focus on only one of the many conditions that a patient may have. If a patient has two diseases with similar clinical manifestations, they may respond differently to a disease-specific instrument if one of their conditions improves while the other worsens or remains stable, thus undermining the instruments in that patient population. We sought empirical evidence of the reliability and validity (including responsiveness) of the Kansas City Cardiomyopathy Questionnaire (KCCQ), a disease-specific measure for heart failure (HF), among HF patients with and without anemia, a condition that has similar symptoms to HF.
  
  
  METHODS
  This work used a prospective cohort study of 811 HF outpatients from 58 U.S. centers with a baseline assessment of anemia of whom 698 were followed for 3 months with serial health status measures.
  
  
  RESULTS
  Among participants, 268 (33%) were anemic. The construct validity of the KCCQ was supported by showing similar correlations with the New York Heart Association (NYHA) classification in patients with and without anemia (P value for interaction = 0.38). The internal consistency (Cronbach's alpha = 0.92 and 0.93 for anemic and non-anemic patients, respectively) and test-retest reliability (mean 3-month change scores in stable patients = -2.8 [SD = 1.4] and -0.5 [SD = 0.8], P = 0.14) were similar. Estimates of responsiveness were also similar.
  
  
  CONCLUSIONS
  This study provides empirical evidence that the psychometric properties of the KCCQ are similar in patients with or without anemia, a potentially confounding clinical condition in patients with heart failure.
authors.affiliation: Mid America Heart Institute, 4401 Wornall Road, Kansas City, MO 64111, USA. spertusj@umkc.edu
authors.forename: John A
authors.initials: JA
authors.lastname: Spertus
authors.forename: Philip G
authors.initials: PG
authors.lastname: Jones
authors.forename: John
authors.initials: J
authors.lastname: Kim
authors.forename: Denise
authors.initials: D
authors.lastname: Globe
mesh_terms: D000368:Aged; D000740:Anemia / Q000150:complications*; D009202:Cardiomyopathies; D005260:Female; D006305:Health Status Indicators; D006333:Heart Failure / Q000150:complications*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010358:Patient Participation; D011446:Prospective Studies; D011594:Psychometrics; D011788:Quality of Life; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires