Searching for the optimal number of response alternatives for the distress scale of the four-dimensional symptom questionnaire.

ABSTRACT: BACKGROUND:The Four-Dimensional Symptom Questionnaire (4DSQ) is a self-report questionnaire designed to measure distress, depression, anxiety, and somatization. Prior to computing scale scores from the item scores, the three highest response alternatives ('Regularly', 'Often', and 'Very often or constantly present') are usually collapsed into one category to reduce the influence of extreme responding on item- and scale scores. In this study, we evaluate the usefulness of this transformation for the distress scale based on a variety of criteria. METHODS:Specifically, by using the Graded Response Model, we investigated the effect of this transformation on model fit, local measurement precision, and various indicators of the scale's validity to get an indication on whether the current practic

SUBMITTER: van Bebber J 

PROVIDER: S-EPMC6439967 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature