우울장애 선별 시 한글판 Patient Health Questionnaire-9의 기준점수(Cut-Off Point)에 대한 타당도 연구

Abstract

Objectives : Depressive disorder is one of mental disorders associated with suicide. PHQ-9 is widely used screening instrument for depression in clinical settings. However, there is considerable divergence of opinion about cutoff points of the PHQ-9. The aim of this study was to find the valid, optimal cutoff points to screen depressive disorders using the Korean version of PHQ-9. Methods : 139 psychiatric patients who were diagnosed as MDD, dysthymic disorder, depressive disorder not otherwise specified, and other non-psychotic psychiatric disorders with the M.I.N.I. PLUS were recruited. Subsequently, the PHQ-9, HDRS, PHQ-15, MMPI-Depression scale were administered. Reliability, validity and the ROC curve analysis were performed. Results : The internal reliability using Cronbach’s alpha was relatively high (Cronbach’s alpha=0.85). In addition, correlations of the PHQ-9 with the HDRS, PHQ-15 and MMPI-Depression scale were 0.691, 0.582, and 0.404_ (p＜.01). Between the depression and non-depression groups, the AUC_ (area under the ROC curve) was 0.712_ (standard error=0.051, p＜.001) and the PHQ-9 had a cut-off point of 6_ (sensitivity 91.5%, specificity 33.3%). Between MDD and non-MDD groups, the AUC was 0.827 (standard error=0.035, p＜.001) and the PHQ-9 had a cut-off point of 10_ (sensitivity 86.5%, specificity 52.9%). Conclusion : The PHQ-9 is considered as a short and valid tool to identify MDD (PHQ-9 total score 10).