Screening for Major Depressive Disorder with the Patient Health Questionnaire (PHQ-9 and PHQ-2) in an Outpatient Clinic Staffed by Primary Care Physicians in Japan: A Case Control Study

• Published in: PloS one Vol. 10; no. 3; p. e0119147
• Main Authors: Suzuki, Keiko, Kumei, Shima, Ohhira, Masumi, Nozu, Tsukasa, Okumura, Toshikatsu
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 19.03.2015; Public Library of Science (PLoS)
• Subjects: Age Factors; Ambulatory Care Facilities; Cardiovascular disease; Case-Control Studies; Depression (Mood disorder); Depressive Disorder, Major - diagnosis; Disorders; Health; Health aspects; Health care; Health surveys; Hospitals; Humans; Internal medicine; Japan; Mass Screening; Medical diagnosis; Medical personnel; Medicine; Mental depression; Middle Aged; Patients; Physicians; Physicians, Primary Care; Primary care; Psychiatry; Quality of life; Questionnaires; ROC Curve; Screening; Sensitivity; Surveys; Surveys and Questionnaires; Validity; Japan
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0119147

The Patient Health Questionnaire (PHQ-9) is a self-report questionnaire commonly used to screen for depression, with ≥8-11 generally recommended as the cut-off. In Japan, studies of the validity of the PHQ-9 and PHQ-2 have been limited. In this study, we examined the utility of the PHQ-9 and PHQ-2 at an outpatient clinic in a Medical University Hospital in Japan. New consecutive outpatients were included in the study. We administered the PHQ-9 to 574 patients, and acquired complete PHQ-9 and PHQ-2 data for 521 patients. Major depressive disorders were diagnosed according to the DSM-IV-TR. Forty-two patients were diagnosed with major depressive disorders. The mean PHQ-9 (15.7) and PHQ-2 (3.8) scores of the patients with major depressive disorders were significantly higher than the scores of the patients without depression (6.0 (PHQ-9) and 1.8 (PHQ-2)). The best cut-off points for the PHQ-9 and PHQ-2 summary scores were ≥11 (sensitivity 0.76, specificity 0.81) and ≥3 (sensitivity 0.76, specificity 0.82), respectively. No relationship was observed between the age and PHQ-9 scores. The PHQ-9 and PHQ-2 were useful instruments for screening for major depressive disorders. The best cut-off point for the PHQ-9 summary score should be ≥11 to detect depression in the primary care setting in Japan.