title: Dyspnea-12 is a valid and reliable measure of breathlessness in patients with interstitial lung disease.
abstract: OBJECTIVE
  In this study, we aimed to determine the validity and reliability of the Dyspnea-12 questionnaire (D-12) for the assessment of breathlessness in patients with interstitial lung disease (ILD).
  
  
  METHODS
  A total of 101 patients with ILD completed the D-12 (scale range, 0-36, with a high score indicating worse dyspnea), Medical Research Council (MRC) dyspnea scale, St. George Respiratory Questionnaire (SGRQ), and Hospital Anxiety and Depression Scale (HADS) at baseline, and 84 patients completed the D-12 and a global health transition score at follow-up 2 weeks later. D-12 psychometric properties, including floor and ceiling effects, internal consistency, test-retest reliability, and construct validity were examined.
  
  
  RESULTS
  The D-12 showed good internal consistency (Cronbach α, 0.93) and repeatability (intraclass correlation coefficient, 0.94). Its scores were significantly associated with MRC grade (r = 0.59; P < .001), SGRQ (symptoms, r = 0.57; activities, r = 0.78; impacts, r = 0.75; total, r = 0.79; P < .001). Factor analysis confirmed the previously determined structure of the D-12 in this patient group.
  
  
  CONCLUSIONS
  In patients with ILD, the D-12, a patient-reported measure of dyspnea severity that requires no reference to activity, is a reliable and valid instrument. It is short, simple to complete, and easy to score.
authors.affiliation: Faculty of Health and Social Care, School of Nursing, University of Salford, Greater Manchester, England. j.yorke@salford.ac.uk
authors.forename: Janelle
authors.initials: J
authors.lastname: Yorke
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Swigris
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Russell
authors.forename: Shakeeb H
authors.initials: SH
authors.lastname: Moosavi
authors.forename: Georges
authors.initials: G
authors.lastname: Ng Man Kwong
authors.forename: Mark
authors.initials: M
authors.lastname: Longshaw
authors.forename: Paul W
authors.initials: PW
authors.lastname: Jones
mesh_terms: D000368:Aged; D004417:Dyspnea / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume; D006801:Humans; D017563:Lung Diseases, Interstitial / Q000150:complications / Q000503:physiopathology*; D008297:Male; D011594:Psychometrics / Q000379:methods; D011788:Quality of Life; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires