title: Reliability and validity of the PHQ-9 for screening late-life depression in Chinese primary care.
abstract: OBJECTIVE
  The aim of this study was to examine the reliability and validation of the 9-item Patient Health Questionnaire (PHQ-9) for late-life depression in Chinese primary care.
  
  
  METHODS
  In the primary care clinics (PCCs) of Hangzhou city, we recruited 364 older patients (aged ≥ 60) for the PHQ-9 screening. Then 77 of them were further interviewed with Structured Clinical Interview for DSM Disorders (SCID) for the diagnosis of major depression in late life. Statistic strategies for the feasibility, reliability, validity, and receiver operating characteristic curve were performed.
  
  
  RESULTS
  The mean administration time was 7.5 min, and the Cronbach's α was 0.91. The optimal cut-off score of PHQ-9 ≥ 9 revealed a sensitivity of 0.86, specificity of 0.77, and positive likelihood ratio of 5.73. The area under the curve (AUC) in this study was 0.92 (SD = 0.02, 95% CI 0.88-0.96). The PHQ-2 also revealed good sensitivity (0.84) and specificity (0.90) at the cut-off point ≥ 3.
  
  
  CONCLUSIONS
  The PHQ-9 performs well and has acceptable psychometric properties for screening of patients with late-life depression in Chinese primary care settings.
authors.affiliation: Department of Psychology and Behavioral Science, Zhejiang University, Hangzhou, China. shulinchen1990@gmail.com
authors.forename: Shulin
authors.initials: S
authors.lastname: Chen
authors.forename: Helen
authors.initials: H
authors.lastname: Chiu
authors.forename: Baihua
authors.initials: B
authors.lastname: Xu
authors.forename: Yan
authors.initials: Y
authors.lastname: Ma
authors.forename: Tao
authors.initials: T
authors.lastname: Jin
authors.forename: Manhua
authors.initials: M
authors.lastname: Wu
authors.forename: Yeates
authors.initials: Y
authors.lastname: Conwell
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D002681:China; D003866:Depressive Disorder / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D011594:Psychometrics / Q000379:methods*; D012372:ROC Curve; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires / Q000592:standards*