title: The structure of the Hospital Anxiety and Depression Scale in four cohorts of community-based, healthy older people: the HALCyon program.
abstract: BACKGROUND
  The Hospital Anxiety and Depression Scale (HADS) is widely used but evaluation of its psychometric properties has produced equivocal results. Little is known about its structure in non-clinical samples of older people.
  
  
  METHODS
  We used data from four cohorts in the HALCyon collaborative research program into healthy aging: the Caerphilly Prospective Study, the Hertfordshire Ageing Study, the Hertfordshire Cohort Study, and the Lothian Birth Cohort 1921. We used exploratory factor analysis and confirmatory factor analysis with multi-group comparisons to establish the structure of the HADS and test for factorial invariance between samples.
  
  
  RESULTS
  Exploratory factor analysis showed a bi-dimensional structure (anxiety and depression) of the scale in men and women in each cohort. We tested a hypothesized three-factor model but high correlations between two of the factors made a two-factor model more psychologically plausible. Multi-group confirmatory factor analysis revealed that the sizes of the respective item loadings on the two factors were effectively identical in men and women from the same cohort. There was more variation between cohorts, particularly those from different parts of the U.K. and in whom the HADS was administered differently. Differences in social-class distribution accounted for part of this variation.
  
  
  CONCLUSIONS
  Scoring the HADS as two subscales of anxiety and depression is appropriate in non-clinical populations of older men and women. However, there were differences between cohorts in the way that individual items were linked with the constructs of anxiety and depression, perhaps due to differences in sociocultural factors and/or in the administration of the scale.
authors.affiliation: MRC Epidemiology Resource Centre, University of Southampton, Southampton SO16 6YD, UK. crg@mrc.soton.ac.uk
authors.forename: Catharine R
authors.initials: CR
authors.lastname: Gale
authors.forename: Michael
authors.initials: M
authors.lastname: Allerhand
authors.forename: Avan Aihie
authors.initials: AA
authors.lastname: Sayer
authors.forename: Cyrus
authors.initials: C
authors.lastname: Cooper
authors.forename: Elaine M
authors.initials: EM
authors.lastname: Dennison
authors.forename: John M
authors.initials: JM
authors.lastname: Starr
authors.forename: Yoav
authors.initials: Y
authors.lastname: Ben-Shlomo
authors.forename: John E
authors.initials: JE
authors.lastname: Gallacher
authors.forename: Diana
authors.initials: D
authors.lastname: Kuh
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Deary
mesh_terms: D000368:Aged; D001008:Anxiety Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology*; D015331:Cohort Studies; D003156:Community Mental Health Services / Q000706:statistics & numerical data*; D003866:Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology*; D005163:Factor Analysis, Statistical; D005260:Female; D006304:Health Status; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D016730:Program Development; D011446:Prospective Studies; D011594:Psychometrics; D011795:Surveys and Questionnaires