title: PHQ-9 and PHQ-2 for Screening Depression in Chinese Rural Elderly.
abstract: OBJECTIVE
  This study aimed to explore cut-off scores of the 9-item Patient Health Questionnaire (PHQ-9) and 2-item Patient Health Questionnaire (PHQ-2) for depression screening in Chinese rural elderly.
  
  
  METHODS
  A cross-sectional study was conducted on 839 residents aged 60 years and above in rural areas of Liuyang County. PHQ-9 was adopted to evaluate depression. The Structured Clinical Interview for DSM Disorders (SCID-I) was adopted to diagnose major depressive disorder (MDD) as a golden standard. Sensitivity, specificity, positive and negative predictive value, positive and negative likelihood ratio, Youden's index and the receiver operating characteristic (ROC) curve were analyzed on PHQ-9 and PHQ-2.
  
  
  RESULTS
  The Cronbach's alphas of PHQ-9 and PHQ-2 were 0.82 and 0.76, respectively. The score of 8 of the PHQ-9 showed the highest Youden's index of 0.85, with a sensitivity of 0.97 and specificity of 0.89 respectively, and the area under the ROC curve (AUC) was 0.97 (95% CI: 0.96-0.98). The score of 3 of PHQ-2 showed the highest Youden's index of 0.79, with both sensitivity and specificity were 0.90 and the AUC was 0.94 (95% CI: 0.90-0.97).
  
  
  CONCLUSIONS
  Both PHQ-9 and PHQ-2 are valid screening instruments for depression in the rural elderly in China, with recommended cut-off scores of 8 and 3 respectively.
authors.affiliation: Department of Social Medicine and Health Management, Xiangya School of Public Health, Central South University, Changsha, Hunan, China.
authors.forename: Zi-Wei
authors.initials: ZW
authors.lastname: Liu
authors.affiliation: Department of Social Medicine and Health Management, Xiangya School of Public Health, Central South University, Changsha, Hunan, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Yu
authors.affiliation: Department of Social Medicine and Health Management, Xiangya School of Public Health, Central South University, Changsha, Hunan, China.
authors.forename: Mi
authors.initials: M
authors.lastname: Hu
authors.affiliation: Department of Social Medicine and Health Management, Xiangya School of Public Health, Central South University, Changsha, Hunan, China.
authors.forename: Hui-Ming
authors.initials: HM
authors.lastname: Liu
authors.affiliation: Department of Social Medicine and Health Management, Xiangya School of Public Health, Central South University, Changsha, Hunan, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhou
authors.affiliation: Department of Social Medicine and Health Management, Xiangya School of Public Health, Central South University, Changsha, Hunan, China.
authors.forename: Shui-Yuan
authors.initials: SY
authors.lastname: Xiao
mesh_terms: D000368:Aged; D002681:China; D003863:Depression / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D012372:ROC Curve; D012424:Rural Population; D011795:Surveys and Questionnaires