title: Diagnostic validity of the Patient Health Questionnaire-2 (PHQ-2) among Ethiopian adults.
abstract: The Patient Health Questionnaire-2 (PHQ-2) is an ultra-brief questionnaire widely used by researchers and clinicians to detect major depressive disorder (MDD). Despite its individual and societal impact, MDD is often undetected and untreated particularly among sub-Saharan Africans. We conducted this study to evaluate the reliability and validity of using the PHQ-2 as a screen for MDD among Ethiopian adults.
  
  
  
  A total of 926 adults attending outpatient departments in a major referral hospital in Addis Ababa, Ethiopia participated in this study. Construct validity was assessed by examining associations of PHQ-2 scores with World Health Organization Quality of Life (WHO-QOL) domains. We assessed criterion validity and performance characteristics against an independent, blinded, and psychiatrist administered semi-structured Schedules for Clinical Assessment in Neuropsychiatry (SCAN) interview using measures of sensitivity, specificity and receiver operating characteristics (ROC) curves.
  
  
  
  The PHQ-2 items showed good reliability (intraclass correlation coefficient=0.92). Quality of life, as reflected by subscale scores for four WHO-QOL domains, was significantly lower among patients with increasing PHQ-2 scores demonstrating good construct validity. ROC analysis and Youden Index showed that a PHQ-2 threshold score of 3 offered optimal discriminatory power with respect to the diagnosis of MDD via the clinical interview (sensitivity=74% and specificity=60%).
  
  
  
  The Amharic language version of the PHQ-2 had good sensitivity and fair specificity for detecting MDD compared against a psychiatrist administered SCAN diagnosis. This study provides evidence for the PHQ-2 as a reliable and valid ultra-brief screening tool for initial identification of MDD.
authors: Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA. Electronic address: bgelaye@hsph.harvard.edu.
authors: Bizu
authors: B
authors: Gelaye
authors: Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
authors: Ijala
authors: I
authors: Wilson
authors: Addis Continental Institute of Public Health, Addis Ababa, Ethiopia.
authors: Hanna Y
authors: HY
authors: Berhane
authors: Faculty of Medicine, Addis Ababa University, Addis Ababa, Ethiopia.
authors: Negussie
authors: N
authors: Deyessa
authors: Faculty of Medicine, Addis Ababa University, Addis Ababa, Ethiopia.
authors: Yonas
authors: Y
authors: Bahretibeb
authors: Faculty of Medicine, Addis Ababa University, Addis Ababa, Ethiopia.
authors: Dawit
authors: D
authors: Wondimagegn
authors: Horizon Health Network, Zone 3, New Brunswick, Canada.
authors: Teshome
authors: T
authors: Shibre Kelkile
authors: Addis Continental Institute of Public Health, Addis Ababa, Ethiopia.
authors: Yemane
authors: Y
authors: Berhane
authors: Departments of Psychiatry and Behavioral Sciences, Rehabilitation Medicine, and Epidemiology, University of Washington, Seattle, WA, USA.
authors: Jesse R
authors: JR
authors: Fann
authors: Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
authors: Michelle A
authors: MA
authors: Williams
mesh_terms: D000328:Adult; D003865:Major Depressive Disorder / Q000175:diagnosis* / Q000453:epidemiology* / Q000523:psychology; D005002:Ethiopia / Q000453:epidemiology; D005260:Female; D006306:Health Surveys / Q000592:standards*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011788:Quality of Life / Q000523:psychology; D012372:ROC Curve; D011897:Random Allocation; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires / Q000592:standards; D055815:Young Adult