title: The attitudes to ageing questionnaire: Mokken scaling analysis.
abstract: BACKGROUND
  Hierarchical scales are useful in understanding the structure of underlying latent traits in many questionnaires. The Attitudes to Ageing Questionnaire (AAQ) explored the attitudes to ageing of older people themselves, and originally described three distinct subscales: (1) Psychosocial Loss (2) Physical Change and (3) Psychological Growth. This study aimed to use Mokken analysis, a method of Item Response Theory, to test for hierarchies within the AAQ and to explore how these relate to underlying latent traits.
  
  
  METHODS
  Participants in a longitudinal cohort study, the Lothian Birth Cohort 1936, completed a cross-sectional postal survey. Data from 802 participants were analysed using Mokken Scaling analysis. These results were compared with factor analysis using exploratory structural equation modelling.
  
  
  RESULTS
  Participants were 51.6% male, mean age 74.0 years (SD 0.28). Three scales were identified from 18 of the 24 items: two weak Mokken scales and one moderate Mokken scale. (1) 'Vitality' contained a combination of items from all three previously determined factors of the AAQ, with a hierarchy from physical to psychosocial; (2) 'Legacy' contained items exclusively from the Psychological Growth scale, with a hierarchy from individual contributions to passing things on; (3) 'Exclusion' contained items from the Psychosocial Loss scale, with a hierarchy from general to specific instances. All of the scales were reliable and statistically significant with 'Legacy' showing invariant item ordering. The scales correlate as expected with personality, anxiety and depression. Exploratory SEM mostly confirmed the original factor structure.
  
  
  CONCLUSIONS
  The concurrent use of factor analysis and Mokken scaling provides additional information about the AAQ. The previously-described factor structure is mostly confirmed. Mokken scaling identifies a new factor relating to vitality, and a hierarchy of responses within three separate scales, referring to vitality, legacy and exclusion. This shows what older people themselves consider important regarding their own ageing.
authors.affiliation: Department of Geriatric Medicine, University of Edinburgh, Edinburgh, Scotland, United Kingdom; Centre for Cognitive Ageing and Cognitive Epidemiology, Edinburgh, Scotland, United Kingdom.
authors.forename: Susan D
authors.initials: SD
authors.lastname: Shenkin
authors.affiliation: Faculty of Health & Social Care, University of Hull, Hull, England, United Kingdom.
authors.forename: Roger
authors.initials: R
authors.lastname: Watson
authors.affiliation: Department of Clinical Psychology, University of East Anglia, Norwich, England, United Kingdom.
authors.forename: Ken
authors.initials: K
authors.lastname: Laidlaw
authors.affiliation: Department of Geriatric Medicine, University of Edinburgh, Edinburgh, Scotland, United Kingdom; Centre for Cognitive Ageing and Cognitive Epidemiology, Edinburgh, Scotland, United Kingdom.
authors.forename: John M
authors.initials: JM
authors.lastname: Starr
authors.affiliation: Centre for Cognitive Ageing and Cognitive Epidemiology, Edinburgh, Scotland, United Kingdom; Department of Psychology, University of Edinburgh, Edinburgh, Scotland, United Kingdom.
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Deary
mesh_terms: D000368:Aged; D000375:Aging / Q000523:psychology*; D001290:Attitude; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D025341:Principal Component Analysis; D011594:Psychometrics / Q000706:statistics & numerical data*; D011795:Surveys and Questionnaires