title: Applying computer adaptive testing to optimize online assessment of suicidal behavior: a simulation study.
abstract: BACKGROUND
  The Internet is used increasingly for both suicide research and prevention. To optimize online assessment of suicidal patients, there is a need for short, good-quality tools to assess elevated risk of future suicidal behavior. Computer adaptive testing (CAT) can be used to reduce response burden and improve accuracy, and make the available pencil-and-paper tools more appropriate for online administration.
  
  
  OBJECTIVE
  The aim was to test whether an item response-based computer adaptive simulation can be used to reduce the length of the Beck Scale for Suicide Ideation (BSS).
  
  
  METHODS
  The data used for our simulation was obtained from a large multicenter trial from The Netherlands: the Professionals in Training to STOP suicide (PITSTOP suicide) study. We applied a principal components analysis (PCA), confirmatory factor analysis (CFA), a graded response model (GRM), and simulated a CAT.
  
  
  RESULTS
  The scores of 505 patients were analyzed. Psychometric analyses showed the questionnaire to be unidimensional with good internal consistency. The computer adaptive simulation showed that for the estimation of elevation of risk of future suicidal behavior 4 items (instead of the full 19) were sufficient, on average.
  
  
  CONCLUSIONS
  This study demonstrated that CAT can be applied successfully to reduce the length of the Dutch version of the BSS. We argue that the use of CAT can improve the accuracy and the response burden when assessing the risk of future suicidal behavior online. Because CAT can be daunting for clinicians and applied scientists, we offer a concrete example of our computer adaptive simulation of the Dutch version of the BSS at the end of the paper.
authors.affiliation: Faculty of Psychology and Education, Department of Clinical Psychology, VU University Amsterdam, Amsterdam, Netherlands. dp.de.beurs@vu.nl.
authors.forename: Derek Paul
authors.identifier: http://orcid.org/0000-0002-0166-6897
authors.initials: DP
authors.lastname: De Beurs
authors.forename: Anton Lm
authors.identifier: http://orcid.org/0000-0002-5786-8551
authors.initials: AL
authors.lastname: de Vries
authors.forename: Marieke H
authors.identifier: http://orcid.org/0000-0003-0171-0322
authors.initials: MH
authors.lastname: de Groot
authors.forename: Jos
authors.identifier: http://orcid.org/0000-0002-7871-9483
authors.initials: J
authors.lastname: de Keijser
authors.forename: Ad Jfm
authors.identifier: http://orcid.org/0000-0003-1701-5332
authors.initials: AJ
authors.lastname: Kerkhof
mesh_terms: D005260:Female; D006801:Humans; D020407:Internet; D009426:Netherlands; D011594:Psychometrics; D012107:Research Design; D018570:Risk Assessment; D012984:Software; D059020:Suicidal Ideation; D011795:Surveys and Questionnaires; D000092864:Suicide Prevention
keywords: Internet; computing methodologies; psychometrics; risk assessment; suicidal ideation; suicide