title: Screening for major and minor depression in a multiethnic sample of Asian primary care patients: a comparison of the nine-item Patient Health Questionnaire (PHQ-9) and the 16-item Quick Inventory of Depressive Symptomatology - Self-Report (QIDS-SR16 ).
abstract: BACKGROUND
  Depression is common, disabling, and the single most important factor leading to suicide, yet it is underdiagnosed in busy primary care settings. A key challenge facing primary care clinicians in Asia is the selection of instruments to facilitate depression screening. Although the nine-item Patient Health Questionnaire (PHQ-9) and 16-item Quick Inventory of Depressive Symptomatology - Self-Report (QIDS-SR16 ) are used internationally, they have not been directly compared or widely validated in Asian primary care populations. This study aimed to validate the PHQ-9 and QIDS-SR16 against a structured interview diagnosis of Diagnostic and Statistical Manual, 4th Edition, depression based on the Mini-International Neuropsychiatric Interview in a multiethnic Asian sample.
  
  
  METHODS
  From April through August 2011, we enrolled 400 English-speaking Singaporean primary care patients. Participants completed a demographic data form, the PHQ-9, and the QIDS-SR16 . They were assessed independently for major and minor depression using the Mini-International Neuropsychiatric Interview.
  
  
  RESULTS
  Sensitivity and specificity for diagnosing major depression were 91.7% and 72.2%, respectively, for the PHQ-9 (optimal cutoff score of 6), and 83.3% and 84.7%, respectively, for the QIDS-SR16 (optimal cutoff score of 9). The QIDS-SR16 also detected minor depression at an optimal cutoff score of 7, with a sensitivity of 94.4% and specificity of 77.9%. The PHQ-9 and QIDS-SR16 showed good internal consistency (Cronbach's α: 0.87 and 0.79, respectively) and good convergent validity (correlation coefficient: r = 0.73, P < 0.001). The overall prevalence of major and minor depressive disorders was 9%.
  
  
  CONCLUSIONS
  The PHQ-9 and QIDS-SR16 appear to be valid and reliable for depression screening in Asian primary care settings.
authors.affiliation: Office of Clinical Sciences, Duke-NUS Graduate Medical School Singapore, Singapore; Department of Child & Adolescent Psychiatry, Institute of Mental Health, Singapore.
authors.forename: Sharon Cohan
authors.initials: SC
authors.lastname: Sung
authors.forename: Charity Cheng Hong
authors.initials: CC
authors.lastname: Low
authors.forename: Daniel Shuen Sheng
authors.initials: DS
authors.lastname: Fung
authors.forename: Yiong Huak
authors.initials: YH
authors.lastname: Chan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D044466:Asian People / Q000523:psychology; D003863:Depression / Q000175:diagnosis / Q000453:epidemiology*; D003866:Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007406:Interview, Psychological; D016015:Logistic Models; D008297:Male; D008403:Mass Screening / Q000379:methods* / Q000592:standards; D008875:Middle Aged; D011320:Primary Health Care; D011569:Psychiatric Status Rating Scales / Q000592:standards* / Q000706:statistics & numerical data; D012307:Risk Factors; D057566:Self Report; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D012846:Singapore / Q000453:epidemiology; D044465:White People / Q000523:psychology; D055815:Young Adult
keywords: depression; depressive disorder; primary health care; questionnaire; self-report