title: Differences in Patient Health Questionnaire and Aachen Depression Item Bank scores between tablet versus paper-and-pencil administration.
abstract: OBJECTIVE
  To extend knowledge about measurement equivalence of depression measures assessed by tablet and paper-pencil administration, the present study evaluated the effect of mode of administration (MoA) on scale and item level for the Patient Health Questionnaire (PHQ-9) and the Aachen Depression Item Bank (ADIB) in elderly patients.
  
  
  METHODS
  Primary care patients (N = 193, ≥60 years) were assessed following a crossover design in Leipzig, Germany. All participants filled out the PHQ-9 and the ADIB in both MoAs under study. Effects of MoA were analyzed by intra-class correlation, mixed-effects regression, and differential item functioning (DIF). Additionally, detection rates between both MoAs were compared using receiver operating characteristics analysis compared to a diagnostic interview (SCID-I, N = 163).
  
  
  RESULTS
  No effect of MoA was found in the PHQ-9 on scale score or item level. Two ADIB items showed DIF according to MoA. In terms of discriminatory power, MoA did not influence detection rates of both instruments.
  
  
  CONCLUSIONS
  In summary, our findings suggest that no severe effect of mode of administration on self-report assessments of depression should be expected. It can be concluded that tablets provide a valid way to electronically assess depressive symptoms in elderly patients. Yet changes in item presentation can influence the psychometric properties and require equivalence testing using sophisticated analyses on item level such as DIF.
authors.affiliation: Department of Medical Psychology and Medical Sociology, University of Leipzig, Philipp-Rosenthal-Str. 55, 04103, Leipzig, Germany. Lena.Spangenberg@medizin.uni-leipzig.de.
authors.forename: Lena
authors.initials: L
authors.lastname: Spangenberg
authors.affiliation: Department of Medical Psychology and Medical Sociology, University of Leipzig, Philipp-Rosenthal-Str. 55, 04103, Leipzig, Germany.
authors.forename: Heide
authors.initials: H
authors.lastname: Glaesmer
authors.affiliation: Institute of Medical Psychology and Medical Sociology, University Hospital of RWTH Aachen, Aachen, Germany.
authors.forename: Maren
authors.initials: M
authors.lastname: Boecker
authors.affiliation: Institute of Medical Psychology and Medical Sociology, University Hospital of RWTH Aachen, Aachen, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Forkmann
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003863:Depression / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011788:Quality of Life / Q000523:psychology*; D012107:Research Design; D057566:Self Report; D011795:Surveys and Questionnaires / Q000706:statistics & numerical data*
keywords: Depression assessment; Elderly; Equivalence testing; Item response theory; Tablet