The Usefulness of the Korean Version of Penn State Worry Questionnaire for Screening Generalized Anxiety Disorder: A Receiver Operating Characteristic Analysis

OBJECTIVE Excessive worry about minor matters and a state in which this worry is experienced as uncontrollable are known to be key symptoms of generalized anxiety disorder (GAD). Given the importance of pathological worry in GAD, the need for psychometrically sound measures of this construct has increased. The purpose of this study was to investigate the usefulness of the Korean version of Penn State Worry Questionnaire (K-PSWQ) for screening GAD. METHODS Two hundred and forty six patients were initially screened, from which 102 GAD patients and 118 patients with anxiety disorder not otherwise specified (anxiety disorder NOS) were finally enrolled. Patients were diagnosed by a structured clinical interview for the DSM-IV Axis I. We also enrolled 114 control subjects who had no medical or psychiatric history. Pathological worry in both patients and control subjects were assessed at baseline using the PSWQ and we estimated optimal cutoff score by the receiver operating characteristic (ROC) analysis. RESULTS We found that in the first ROC analysis, a score of 53 could simultaneously optimize sensitivity and specificity in order to discriminate GAD patients from control subjects. From the second receiver operating characteristic analysis, when both sensitivity and specificity were optimized, we can suggest a score of 61 as being the cutoff for differentiating GAD patients from patients with anxiety disorder NOS. CONCLUSION The Korean version of PSWQ is a useful method for screening GAD patients, although ethnic and cultural differences may affect the cutoff score of PSWQ for GAD.