title: Reliability and validity of the Chinese version of the Patient Health Questionnaire (PHQ-9) in the general population.
abstract: OBJECTIVE
  Depression is one of the most common mental illnesses. The reliability and the validity of the Patient Health Questionnaire (PHQ)-9, a depression screening tool, have not been examined in the general population in China. Thus, this study evaluated the reliability and the validity of the Chinese version of the PHQ-9 in detecting major depression in residents of a Chinese community.
  
  
  METHODS
  A total of 1045 participants from a Shanghai community were enrolled in our study. Participants completed the Chinese versions of the PHQ-9, the Self-Rating Depression Scale (SDS), the 36-item Short Form Health Survey (SF-36), and the Mini International Neuropsychiatric Interview. One hundred participants were randomly selected to complete the PHQ-9 again 2 weeks after the initial assessment. The reliability, the validity and the receiver operating characteristic (ROC) curve of the PHQ-9 were analyzed.
  
  
  RESULTS
  Cronbach's alpha for the internal consistency reliability of the Chinese version of the PHQ-9 was 0.86 for the entire scale. The correlation coefficient for the 2-week test-retest of the total score was 0.86. The PHQ-9 scale correlated positively with the SDS (r=0.29, p<0.001) and correlated negatively with all subscale scores of the SF-36 (correlation coefficients ranged from -0.11 to -0.47, p<0.001). The area under the curve of the ROC was 0.92 (95% confidence interval: 0.86-0.97). A cutoff score of 7 or higher on the PHQ-9 had a sensitivity of 0.86 and a specificity of 0.86.
  
  
  CONCLUSIONS
  In the general Chinese population, the Chinese version of the PHQ-9 is a valid and efficient tool for screening depression, with a recommended cutoff score of 7 or more.
authors.affiliation: Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Wenzheng
authors.initials: W
authors.lastname: Wang
authors.affiliation: Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Bian
authors.affiliation: Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Li
authors.affiliation: Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Wenwen
authors.initials: W
authors.lastname: Wang
authors.affiliation: Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Du
authors.affiliation: Mental Health Center, Xuhui Center for Disease Control and Prevention, Shanghai, China.
authors.forename: Guofang
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Mental Health Center, Xuhui Center for Disease Control and Prevention, Shanghai, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China. Electronic address: drminzhao@gmail.com.
authors.forename: Min
authors.initials: M
authors.lastname: Zhao
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002681:China; D003865:Major Depressive Disorder / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales / Q000592:standards*; D011594:Psychometrics / Q000295:instrumentation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
keywords: Cut-off; Depression; PHQ-9; Sensitivity; Specificity