Evaluation of Computerized Adaptive Tests (CATs) for longitudinal monitoring of depression, anxiety, and stress reactions

Background: Computerized adaptive testing (CAT) based on Item Response Theory, (IRT) offers an efficient way for accurate measurement of patient reported outcomes. The efficiency lies within a minimal response burden and a high measurement precision over a broad measurement range. The objective of the study was to evaluate and compare the responsiveness of CATs measuring anxiety, depression, and stress reaction to standard static self-assessment tools. Methods: Longitudinal data of n=595 psychosomatic inpatients were analyzed for evaluating retest-reliability and sensitivity to change of the CATs compared to static measures (GAD-7, PHQ-9, and PSQ) using correlational and ANOVA statistics. The study hypothesized that CATs are at least as retest-reliable and as sensitive to change as static tools. Results: The three CATs show a low burden for patients, administering on average 5-7 (+/- 2-6SD) items with similar retest-reliability compared to the static tools applied (A-CAT: r=.78 vs. GAD-7: r=.75, D-CAT: r=.71 vs. PHQ-9: r=.75, S-CAT: r=.80 vs. PSQworries scale: r=.80). The CATs were overall as sensitive to change as the static tools (Cohen's d ranged between .19 and .69). Limitations: This is a monocenter, observational, longitudinal study without external clinical criteria; thus generalization to other settings may be limited. Conclusions: The tested CATs belong to the first generation of CATs being used in daily routine for more than a decade. They are as retest reliable and sensitive to change as static tools. Newer CATs may provide further practical advantages. (C) 2014 Elsevier B.V. All rights reserved.