title: A psychometric evaluation of the four-item version of the Control Attitudes Scale for patients with cardiac disease and their partners.
abstract: BACKGROUND
  The four-item Control Attitudes Scale (CAS) was developed to measure control perceived by patients with cardiac disease and their family members, but extensive psychometric evaluation has not been performed.
  
  
  OBJECTIVE
  The aim was to translate, culturally adapt and psychometrically evaluate the CAS in a Swedish sample of implantable cardioverter defibrillator (ICD) recipients, heart failure (HF) patients and their partners.
  
  
  METHODS
  A sample (n=391) of ICD recipients, HF patients and partners were used. Descriptive statistics, item-total and inter-item correlations, exploratory factor analysis, ordinal regression modelling and Cronbach's alpha were used to validate the CAS.
  
  
  RESULTS
  The findings from the factor analyses revealed that the CAS is a multidimensional scale including two factors, Control and Helplessness. The internal consistency was satisfactory for all scales (α=0.74-0.85), except the family version total scale (α=0.62). No differential item functioning was detected which implies that the CAS can be used to make invariant comparisons between groups of different age and sex.
  
  
  CONCLUSIONS
  The psychometric properties, together with the simple and short format of the CAS, make it to a useful tool for measuring perceived control among patients with cardiac diseases and their family members. When using the CAS, subscale scores should be preferred.
authors.affiliation: Department of Medical and Health Sciences, Division of Nursing Science, Linköping University, Linköping, Sweden Faculty of Health and Life Sciences, School of Health and Caring Sciences, Linnaeus University, Kalmar, Sweden Palliative Research Centre, Ersta Sköndal University Collage and Ersta Hospital, Stockholm, Sweden kristofer.arestedt@liu.se.
authors.forename: Kristofer
authors.initials: K
authors.lastname: Årestedt
authors.affiliation: Department of Medical and Health Sciences, Division of Nursing Science, Linköping University, Linköping, Sweden.
authors.forename: Susanna
authors.initials: S
authors.lastname: Ågren
authors.affiliation: Department of Medical and Health Sciences, Division of Nursing Science, Linköping University, Linköping, Sweden.
authors.forename: Inger
authors.initials: I
authors.lastname: Flemme
authors.affiliation: College of Nursing, University of Kentucky, Lexington, KY, United States.
authors.forename: Debra K
authors.initials: DK
authors.lastname: Moser
authors.affiliation: Department of Medical and Health Sciences, Division of Nursing Science, Linköping University, Linköping, Sweden Department of Cardiology, County Council of Östergötland, Linköping, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Strömberg
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D017147:Defibrillators, Implantable / Q000523:psychology; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006333:Heart Failure / Q000523:psychology* / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D011594:Psychometrics; D015203:Reproducibility of Results; D012649:Self Concept; D012737:Sex Factors; D018454:Spouses / Q000523:psychology*; D011795:Surveys and Questionnaires; D013548:Sweden
keywords: Family; heart disease; prevention and control; psychometrics