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.

BACKGROUND: Anxiety 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? METHODS: We 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. RESULTS: Total 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. CONCLUSIONS: The 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.

A validation study of the Four-Dimensional Symptom Questionnaire (4DSQ) in insurance medicine.

OBJECTIVE: This study aimed to evaluate the criterion validity and the diagnostic accuracy of the Four-Dimensional Symptom Questionnaire (4DSQ) regarding the identification of depressive and anxiety disorders in an insurance medicine setting. PARTICIPANTS: Our sample consisted of 230 individuals who applied for a work disability benefit due to mental health problems. METHODS: Depressive and anxiety disorders were assessed using the 4DSQ and the Composite International Diagnostic Interview (CIDI). Internal consistency was determined by calculating Cronbach's alpha values. Criterion validity was evaluated by regression techniques. A Receiver Operating Characteristic (ROC) analysis was performed to evaluate diagnostic accuracy. RESULTS: Of the 230 participants 109 (47.4%) had a current DSM-IV depressive disorder and 146 (63.5%) an anxiety disorder. The 4DSQ scales showed an excellent internal consistency. The depression scale of the 4DSQ had specific sensitivity for major depressive disorder. The anxiety scale was also sensitive for the anxiety disorders. The area under the ROC curve (AUC) indicated good diagnostic accuracy of the 4DSQ for assessing depressive and/or anxiety disorders: AUC-value 0.81 for both depression and anxiety. CONCLUSIONS: Although the 4DSQ shows good criterion validity and diagnostic accuracy with respect to depressive and anxiety disorders in applicants for a work disability benefit due to mental health problems, the feasibility of the 4DSQ as a screening measure for depressive and anxiety disorders is limited due to the high prevalence of depressive and anxiety disorders.