title: Adaptive screening for depression--recalibration of an item bank for the assessment of depression in persons with mental and somatic diseases and evaluation in a simulated computer-adaptive test environment.
abstract: OBJECTIVE
  This study conducted a simulation study for computer-adaptive testing based on the Aachen Depression Item Bank (ADIB), which was developed for the assessment of depression in persons with somatic diseases. Prior to computer-adaptive test simulation, the ADIB was newly calibrated.
  
  
  METHODS
  Recalibration was performed in a sample of 161 patients treated for a depressive syndrome, 103 patients from cardiology, and 103 patients from otorhinolaryngology (mean age 44.1, SD=14.0; 44.7% female) and was cross-validated in a sample of 117 patients undergoing rehabilitation for cardiac diseases (mean age 58.4, SD=10.5; 24.8% women). Unidimensionality of the itembank was checked and a Rasch analysis was performed that evaluated local dependency (LD), differential item functioning (DIF), item fit and reliability. CAT-simulation was conducted with the total sample and additional simulated data.
  
  
  RESULTS
  Recalibration resulted in a strictly unidimensional item bank with 36 items, showing good Rasch model fit (item fit residuals<|2.5|) and no DIF or LD. CAT simulation revealed that 13 items on average were necessary to estimate depression in the range of -2 and +2 logits when terminating at SE≤0.32 and 4 items if using SE≤0.50. Receiver Operating Characteristics analysis showed that θ estimates based on the CAT algorithm have good criterion validity with regard to depression diagnoses (Area Under the Curve≥.78 for all cut-off criteria).
  
  
  CONCLUSIONS
  The recalibration of the ADIB succeeded and the simulation studies conducted suggest that it has good screening performance in the samples investigated and that it may reasonably add to the improvement of depression assessment.
authors.affiliation: Institute of Medical Psychology and Medical Sociology, University Hospital of RWTH Aachen, Germany. Electronic address: tforkmann@ukaachen.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Forkmann
authors.forename: Ulf
authors.initials: U
authors.lastname: Kroehne
authors.forename: Markus
authors.initials: M
authors.lastname: Wirtz
authors.forename: Christine
authors.initials: C
authors.lastname: Norra
authors.forename: Harald
authors.initials: H
authors.lastname: Baumeister
authors.forename: Siegfried
authors.initials: S
authors.lastname: Gauggel
authors.forename: Atilla Halil
authors.initials: AH
authors.lastname: Elhan
authors.forename: Alan
authors.initials: A
authors.lastname: Tennant
authors.forename: Maren
authors.initials: M
authors.lastname: Boecker
mesh_terms: D000328:Adult; D000368:Aged; D003863:Depression / Q000175:diagnosis* / Q000209:etiology; D003866:Depressive Disorder / Q000175:diagnosis* / Q000209:etiology; D005260:Female; D006331:Heart Diseases / Q000523:psychology*; D006801:Humans; D008297:Male; D008403:Mass Screening; D001523:Mental Disorders / Q000150:complications*; D008875:Middle Aged; D011594:Psychometrics; D012372:ROC Curve; D015203:Reproducibility of Results; D012984:Software; D011795:Surveys and Questionnaires
keywords: CAT; Computer-adaptive test; Depression; Item response theory; Rasch model; Screening