title: Screening for depression with the Patient Health Questionnaire-2 (PHQ-2) among the general population in Hong Kong.
abstract: BACKGROUND
  This study investigates the psychometric properties of the Patient Health Questionnaire-2 (PHQ-2) in the general population of Hong Kong.
  
  
  METHODS
  Random sampling was used to recruit 6028 participants aged 15 years or over. Among them, 203 were surveyed twice within a two-week period. Participants completed the Chinese version of the PHQ-9 (including 2 items of the PHQ-2), the Chinese Health Questionnaire, the Happiness Scale, the SF-12, and questions about diagnosis and health service utilization. Internal consistency, test-retest reliability, construct and discriminant validity of the PHQ-2 were assessed.
  
  
  RESULTS
  Cronbach's α was 0.76. The test-retest reliability over two weeks calculated by intraclass correlation was 0.70. Spearman correlation results showed that the PHQ-2 score was associated with the remaining seven items of the PHQ-9 (r = 0.53), the Chinese Health Questionnaire (r = 0.37), and the Happiness scale (r = -0.32). As expected, the strength of the correlation between the PHQ-2 and the SF-12 Physical Component Summary was lower (r = -0.29) than that with the SF-12 Mental Component Summary (r = -0.50). Participants with higher PHQ-2 scores more frequently reported having received a depression diagnosis made by a doctor, having chronic illness, using medicine, and utilizing health services. Using the cutoff point ≥ 3, 4.2% of participants screened positive for Major Depressive Disorder.
  
  
  CONCLUSIONS
  We did not use diagnostic interviews or other depression measures to test the PHQ-2's relative performance in screening for depression.
  
  
  CONCLUSIONS
  This study provides evidence for the PHQ-2 as a reliable and valid screening tool for depressive symptoms among a randomly recruited community sample in Hong Kong.
authors.affiliation: School of Public Health, The University of Hong Kong, Hong Kong, China.
authors.forename: Xiaonan
authors.initials: X
authors.lastname: Yu
authors.forename: Sunita M
authors.initials: SM
authors.lastname: Stewart
authors.forename: Paul T K
authors.initials: PT
authors.lastname: Wong
authors.forename: Tai Hing
authors.initials: TH
authors.lastname: Lam
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D044466:Asian People; D003863:Depression / Q000175:diagnosis*; D003866:Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology; D005260:Female; D006723:Hong Kong; D006801:Humans; D007802:Language; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics / Q000295:instrumentation* / Q000706:statistics & numerical data; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D055815:Young Adult