This is a protocol for a Cochrane Review (diagnostic). The objectives are as follows:

To determine the diagnostic test accuracy (DTA) of the following five widely used self-reporting questionnaires for detecting anxiety disorders against standardized or structured clinical interviews as the reference standard among adults in any setting. This is a generic protocol for four parallel Cochrane Reviews of DTA.

Review 1. Generalized Anxiety Disorder 7-item (GAD-7) Scale and its short version Generalized Anxiety Disorder 2-item (GAD-2) Scale

Review 2. Hospital Anxiety and Depression Scale (HADS)

Review 3. Beck Anxiety Inventory (BAI)

Review 4. State-Trait Anxiety Inventory (STAI)

In the primary analyses, DTA will be determined separately for the detection of the two target conditions 'any anxiety disorder' and 'generalized anxiety disorder'. If at least three studies present data on other specified anxiety disorders (e.g. panic disorder or social phobia), DTA will be determined also for these conditions.

Secondary objectives

To investigate whether the DTA varies depending on the prevalence of anxiety disorders in the study population, setting, the reference standard and the risk of bias and to understand how diagnostic performance changes with test threshold.