Differences in Patient Health Questionnaire and Aachen Depression Item Bank scores between tablet versus paper-and-pencil administration

Abstract

Purpose: 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.

Keywords: Depression assessment; Elderly; Equivalence testing; Item response theory; Tablet.