Risk of bias, applicability concerns and data reporting in diagnostic test accuracy studies of questionnaires used for anxiety screening - Lessons from six systematic reviews.

BACKGROUND: This article aims to provide an overview of the risk of bias, concerns regarding applicability, and the reporting of findings from studies examining the diagnostic test accuracy (DTA) of self-report questionnaires used to screen for anxiety disorders. METHODS: We merged data from 103 studies included in six systematic reviews on the diagnostic accuracy of eight anxiety questionnaires (HADS-A, GAD-7, GAD-2, BAI, STAI-S, STAI-T, PROMIS-A-SF8a, and OASIS) in adults. To be included, primary studies had to report the sensitivity and specificity for at least one cut-off when tested against a (semi-)structured clinical interview used as a reference standard. Risk of bias and applicability were rated with the QUADAS-2 tool (Quality Assessment of Diagnostic Accuracy Studies). RESULTS: The 103 studies involved a total of 34,833 participants (range 48 to 3215). The most commonly used questionnaires were the HADS-A (54 studies), the GAD-7 (46), and the GAD-2 (31). Overall, 80% of the studies were rated as having unclear or high risk of bias, and for 88%, concerns regarding applicability were rated as unclear or high. Uncertainties or concerns were particularly common regarding participant recruitment and whether the samples included reflected realistic screening populations. Publications often reported sensitivity and specificity in a very selective manner for a single or a few cut-offs only. CONCLUSIONS: Most DTA studies on questionnaires used to screen for anxiety have significant shortcomings in the reporting of methods and results. Our findings provide a basis for recommendations for future studies.