title: Factor structure of the Hospital Anxiety and Depression Scale (HADS) in German coronary heart disease patients.
abstract: BACKGROUND
  Depression and anxiety in patients with coronary heart disease (CHD) are associated with a poorer prognosis. Therefore the screening for psychological distress is strongly recommended in cardiac rehabilitation. The Hospital Anxiety and Depression Scale (HADS) is a widely used screening tool that has demonstrated good sensitivity and specificity for mental disorders.
  
  
  METHODS
  We assessed mental distress in in-patient cardiac rehabilitation in Germany. The factor structure of the German language version of the HADS was investigated in 1320 patients with CHD. Exploratory factor analysis and confirmatory factor analysis were used to determine the underlying factor structure of the instrument.
  
  
  RESULTS
  Three-factor models were found to offer a superior fit to the data compared to two-factor (anxiety and depression) models. The German language HADS performs similarly to the English language version of the instrument in CHD patients. The German language HADS fundamentally comprises a tri-dimensional underlying factor structure (labelled by Friedman et al. as psychomotor agitation, psychic anxiety and depression).
  
  
  CONCLUSIONS
  Despite of clinical usefulness in screening for mental disturbances the construct validity of the HADS is not clear. The resulting scores of the tri-dimensional model can be interpreted as psychomotor agitation, psychic anxiety, and depression in individual patient data or clinical investigations.
authors.affiliation: University of Freiburg - Institute of Psychology, Department of Rehabilitation Psychology, 79085 Freiburg, Germany. mail@juergen-barth.de
authors.forename: Jürgen
authors.initials: J
authors.lastname: Barth
authors.forename: Colin R
authors.initials: CR
authors.lastname: Martin
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D001007:Anxiety / Q000175:diagnosis*; D002681:China; D003863:Depression / Q000175:diagnosis*; D005163:Factor Analysis, Statistical; D005260:Female; D005858:Germany; D006760:Hospitalization; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000208:ethnology / Q000523:psychology* / Q000534:rehabilitation; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics / Q000295:instrumentation*; D012047:Rehabilitation Centers; D018434:Sickness Impact Profile; D011795:Surveys and Questionnaires; D014175:Translating