title: The dimensional structure of the MacNew Health Related Quality of Life questionnaire: A Mokken Scale Analysis.
abstract: OBJECTIVE
  The MacNew Health related Quality of Life Questionnaire is a widely used instrument for the assessment of health related quality of life in cardiac patients. The study addresses for the first time the dimensional structure of the MacNew with Mokken Scale Analysis (MSA).
  
  
  METHODS
  Separate exploratory MSA of the MacNew was conducted in a large Spanish (n=1012) and a medium sized Austrian sample (n=262) of patients with Coronary Artery Disease (CAD) after Percutaneous Coronary Intervention (PCI). The results of both samples were summarized in a synthesis model. Confirmatory MSA and Confirmatory Factor Analysis (CFA) were used to evaluate the model.
  
  
  RESULTS
  The synthesis model comprises 21 items forming a unidimensional sum scale of moderate strength. On the level of subdomains we define two strong unidimensional subscales (restriction: 6 items, and emotional: 10 items) and two smaller item sets (symptoms: 2 items and social: 3 items). 5 items were excluded due to low scalability in both samples.
  
  
  CONCLUSIONS
  Our results generally support the use of the MacNew Global score, with the limitation, that five items may be questionable with regard to scalability. On the level of unidimensional subscales MSA suggests to differentiate between a six-item restriction scale and a ten-item emotional scale. The study demonstrates that Mokken Scale Analysis complements the results of factor analysis and can contribute to a more comprehensive understanding of the dimensional structure of Health-related Quality of Life questionnaires.
authors.affiliation: Karl Landsteiner Institute for Scientific Research in Clinical Cardiology, Vienna, Austria. Electronic address: o.friedrich@gmx.at.
authors.forename: O
authors.initials: O
authors.lastname: Friedrich
authors.affiliation: Karl Landsteiner Institute for Scientific Research in Clinical Cardiology, Vienna, Austria; Department of Cardiology, Hanusch Krankenhaus, Vienna, Austria.
authors.forename: J
authors.initials: J
authors.lastname: Sipötz
authors.affiliation: Department of Interventional Cardiology, Academic Hospital, Feldkirch, Austria.
authors.forename: W
authors.initials: W
authors.lastname: Benzer
authors.affiliation: Karl Landsteiner Institute for Scientific Research in Clinical Cardiology, Vienna, Austria; Department of Cardiology, Hanusch Krankenhaus, Vienna, Austria.
authors.forename: E
authors.initials: E
authors.lastname: Kunschitz
authors.affiliation: Department of Medical Psychology, Innsbruck Medical University, Austria.
authors.forename: S
authors.initials: S
authors.lastname: Höfer
mesh_terms: D000368:Aged; D002318:Cardiovascular Diseases / Q000523:psychology*; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008960:Models, Psychological; D011788:Quality of Life / Q000523:psychology*; D011795:Surveys and Questionnaires
keywords: Coronary Artery Disease; Health related quality of Life; MacNew; Mokken Scale Analysis