title: Measuring patient anxiety in primary care: Rasch analysis of the 6-item Spielberger State Anxiety Scale.
abstract: OBJECTIVE
  The 6-item Spielberger State Anxiety Scale has been used as a replacement of the original version in many health-care studies. The purpose of this study was to evaluate the measurement properties of the shortened 6-item Spielberger State Anxiety Scale using Rasch analysis in general medical practice patients (N=297).
  
  
  METHODS
  Participants (aged 16 years or above) were recruited on a consecutive basis from three general medical practices. Prior to their appointment, participants were asked to complete a 6-item Spielberger State Anxiety Scale.
  
  
  RESULTS
  The results of the study showed that the scale is unidimentional, and each item measures a different level of patient anxiety. The rating scale operated well and item and person reliability was good. Furthermore, principal-components analysis of the residuals confirmed the scale measures a unitary concept. A scoring key was generated to allow conversion of raw scores to a continuous measurement.
  
  
  CONCLUSIONS
  The 6-item Spielberger State Anxiety Scale is shorter than the original version and has good psychometric properties. This would suggest the scale is a valid alternative to the full version for use in primary health-care practice and research.
authors.affiliation: School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK. waltersh1@cardiff.ac.uk
authors.forename: Helen
authors.initials: H
authors.lastname: Court
authors.forename: Katy
authors.initials: K
authors.lastname: Greenland
authors.forename: Tom H
authors.initials: TH
authors.lastname: Margrain
mesh_terms: D000328:Adult; D000367:Age Factors; D001007:Anxiety / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011320:Primary Health Care / Q000706:statistics & numerical data*; D011594:Psychometrics / Q000295:instrumentation*; D015203:Reproducibility of Results; D012737:Sex Factors; D011795:Surveys and Questionnaires; D014852:Wales