To what extent does the anxiety scale of the Four-Dimensional Symptom Questionnaire (4DSQ) detect specific types of anxiety disorder in primary care? A psychometric study.

Berend Terluin,Annemieke Van Straten,Desiree B Oosterbaan,Wendy Langerak,Harm Wj Van Marwijk,Evelien Pm Brouwers,Peter M Van De Ven

doi:10.1186/1471-244x-14-121

Abstract

BackgroundAnxiety scales may help primary care physicians to detect specific anxiety disorders among the many emotionally distressed patients presenting in primary care. The anxiety scale of the Four-Dimensional Symptom Questionnaire (4DSQ) consists of an admixture of symptoms of specific anxiety disorders. The research questions were: (1) Is the anxiety scale unidimensional or multidimensional? (2) To what extent does the anxiety scale detect specific DSM-IV anxiety disorders? (3) Which cut-off points are suitable to rule out or to rule in (which) anxiety disorders?MethodsWe analyzed 5 primary care datasets with standardized psychiatric diagnoses and 4DSQ scores. Unidimensionality was assessed through confirmatory factor analysis (CFA). We examined mean scores and anxiety score distributions per disorder. Receiver operating characteristic (ROC) analysis was used to determine optimal cut-off points.ResultsTotal n was 969. CFA supported unidimensionality. The anxiety scale performed slightly better in detecting patients with panic disorder, agoraphobia, social phobia, obsessive compulsive disorder (OCD) and post traumatic stress disorder (PTSD) than patients with generalized anxiety disorder (GAD) and specific phobia. ROC-analysis suggested that ≥4 was the optimal cut-off point to rule out and ≥10 the cut-off point to rule in anxiety disorders.ConclusionsThe 4DSQ anxiety scale measures a common trait of pathological anxiety that is characteristic of anxiety disorders, in particular panic disorder, agoraphobia, social phobia, OCD and PTSD. The anxiety score detects the latter anxiety disorders to a slightly greater extent than GAD and specific phobia, without being able to distinguish between the different anxiety disorder types. The cut-off points ≥4 and ≥10 can be used to separate distressed patients in three groups with a relatively low, moderate and high probability of having one or more anxiety disorders.

Highlights

Anxiety scales may help primary care physicians to detect specific anxiety disorders among the many emotionally distressed patients presenting in primary care
The present study evaluated the Four-dimensional symptom questionnaire (4DSQ) anxiety scale as a case finding tool to identify anxiety disorder and aimed to answer the following questions: (1) Is the 4DSQ anxiety scale unidimensional or multidimensional and what is the scale’s reliability? (2) To what extent does the 4DSQ anxiety scale detect each of the specific anxiety disorder types? (3) Which cut-off points are suitable to rule out or to rule in anxiety disorders?
Notwithstanding the fact that the 4DSQ anxiety scale consists of an admixture of vague anxiety symptoms and symptoms that are more or less specific to distinct anxiety disorder types the anxiety scale symptoms appear to work together to measure a common dimension of pathological anxiety

Summary

Introduction

Anxiety scales may help primary care physicians to detect specific anxiety disorders among the many emotionally distressed patients presenting in primary care. For use in primary care practice general scales are more relevant because of their promise to detect all or most types of anxiety disorder (i.e., panic disorder, agoraphobia, social phobia, generalized anxiety disorder (GAD), posttraumatic stress disorder (PTSD), obsessive compulsive disorder (OCD) and specific phobia). A solution to this problem might be the use of a case finding instrument to distinguish between patients with high risk of having an anxiety disorder and patients with low risk. This tool must be robust to prevalence variations as GPs will use it in patient populations with various prevalence rates

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Conclusion