title: Instruments assessing anxiety in adults with intellectual disabilities: a systematic review.
abstract: BACKGROUND
  In the last decades several instruments measuring anxiety in adults with intellectual disabilities have been developed.
  
  
  OBJECTIVE
  To give an overview of the characteristics and psychometric properties of self-report and informant-report instruments measuring anxiety in this group.
  
  
  METHODS
  Systematic review of the literature.
  
  
  RESULTS
  Seventeen studies studying 14 different instruments were found. Methodological quality as measured with the Quality Assessment of Diagnostic Accuracy Studies checklist was insufficient for four studies, sufficient for seven, and good for six. For self-report, the Glasgow Anxiety Scale for people with a learning disability appears most promising, with good internal consistency (a = 0.96), high test-retest reliability (r = 0.95), sensitivity (100%) and specificity (100%). For informant-report, the general anxiety subscale of the Anxiety, Depression and Mood Scale may be promising, with good internal consistency (a = 0.83 and a = 0.84) and excellent test-retest reliability (ICC = 0.78 and ICC = 0.92), but poor interrater reliability (ICC = 0.39).
  
  
  CONCLUSIONS
  Two instruments appear promising. However, these instruments have only been studied once or twice, whereas the methodological quality of these studies was varying.
authors.affiliation: Department of General Practice, Erasmus University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, The Netherlands. h.hermans.1@erasmusmc.nl
authors.forename: Heidi
authors.initials: H
authors.lastname: Hermans
authors.forename: Femke H
authors.initials: FH
authors.lastname: van der Pas
authors.forename: Heleen M
authors.initials: HM
authors.lastname: Evenhuis
mesh_terms: D000328:Adult; D001008:Anxiety Disorders / Q000175:diagnosis* / Q000523:psychology*; D006801:Humans; D008607:Intellectual Disability / Q000523:psychology*; D011569:Psychiatric Status Rating Scales / Q000592:standards*; D015203:Reproducibility of Results