title: Validity and Utility of the Patient Health Questionnaire (PHQ)-2 and PHQ-9 for Screening and Diagnosis of Depression in Rural Chiapas, Mexico: A Cross-Sectional Study.
abstract: BACKGROUND
  Depressive disorders are frequently under diagnosed in resource-limited settings because of lack of access to mental health care or the inability of healthcare providers to recognize them. The Patient Health Questionnaire (PHQ)-2 and the PHQ-9 have been widely used for screening and diagnosis of depression in primary care settings; however, the validity of their use in rural, Spanish-speaking populations is unknown.
  
  
  METHODS
  We used a cross-sectional design to assess the psychometric properties of the PHQ-9 for depression diagnosis and estimated the sensitivity and specificity of the PHQ-2 for depression screening. Data were collected from 223 adults in a rural community of Chiapas, Mexico, using the PHQ-2, the PHQ-9, and the World Health Organization Quality of Life BREF Scale (WHOQOL- BREF).
  
  
  RESULTS
  Confirmatory factor analysis suggested that the 1-factor structure fit reasonably well. The internal consistency of the PHQ-9 was good (Cronbach's alpha > = 0.8) overall and for subgroups defined by gender, literacy, and age. The PHQ-9 demonstrated good predictive validity: Participants with a PHQ-9 diagnosis of depression had lower quality of life scores on the overall WHOQOL-BREF Scale and each of its domains. Using the PHQ-9 results as a gold standard, the optimal PHQ-2 cutoff score for screening of depression was 3 (sensitivity 80.00%, specificity 86.88%, area under receiver operating characteristic curve = 0.89; 95% confidence interval [0.84, 0.94]).
  
  
  CONCLUSIONS
  The PHQ-2 and PHQ-9 demonstrated good psychometric properties, suggesting their potential benefit as tools for depression screening and diagnosis in rural, Spanish-speaking populations.
authors.affiliation: Harvard T.H. Chan School of Public Health.|Harvard Medical School.|Partners In Health/Compañeros En Salud.
authors.forename: Jafet
authors.initials: J
authors.lastname: Arrieta
authors.affiliation: Partners In Health/Compañeros En Salud.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Aguerrebere
authors.affiliation: Harvard Medical School.|Partners In Health/Compañeros En Salud.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Raviola
authors.affiliation: Harvard Medical School.|Partners In Health/Compañeros En Salud.|Brigham and Women's Hospital.
authors.forename: Hugo
authors.initials: H
authors.lastname: Flores
authors.affiliation: Harvard Medical School.|Partners In Health/Compañeros En Salud.|Brigham and Women's Hospital.
authors.forename: Patrick
authors.initials: P
authors.lastname: Elliott
authors.affiliation: Partners In Health/Compañeros En Salud.
authors.forename: Azucena
authors.initials: A
authors.lastname: Espinosa
authors.affiliation: Partners In Health/Compañeros En Salud.
authors.forename: Andrea
authors.initials: A
authors.lastname: Reyes
authors.affiliation: National Institute of Public Health.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Ortiz-Panozo
authors.affiliation: Tecnologico de Monterrey School of Medicine.
authors.forename: Elena G
authors.initials: EG
authors.lastname: Rodriguez-Gutierrez
authors.affiliation: Harvard Medical School.|Partners In Health/Compañeros En Salud.|Brigham and Women's Hospital.
authors.forename: Joia
authors.initials: J
authors.lastname: Mukherjee
authors.affiliation: Harvard Medical School.|Partners In Health/Compañeros En Salud.|Brigham and Women's Hospital.
authors.forename: Daniel
authors.initials: D
authors.lastname: Palazuelos
authors.affiliation: Harvard Medical School.
authors.forename: Molly F
authors.initials: MF
authors.lastname: Franke
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D003863:Depression / Q000175:diagnosis; D003866:Depressive Disorder / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008800:Mexico; D008875:Middle Aged; D000073222:Patient Health Questionnaire / Q000592:standards*; D011594:Psychometrics / Q000295:instrumentation*; D015203:Reproducibility of Results; D012424:Rural Population; D012680:Sensitivity and Specificity; D035862:Vulnerable Populations / Q000523:psychology*; D055815:Young Adult
keywords: mental health care; primary care; validation