Validity/reliability of PHQ-9 and PHQ-2 depression scales among adults living with HIV/AIDS in western Kenya

J Gen Intern Med. 2009 Feb;24(2):189-97. doi: 10.1007/s11606-008-0846-z. Epub 2008 Nov 20.


Background: Depression greatly burdens sub-Saharan Africa, especially populations living with HIV/AIDS, for whom few validated depression scales exist. Patient Health Questionnaire-9 (PHQ-9), a brief dual-purpose instrument yielding DSM-IV diagnoses and severity, and PHQ-2, an ultra-brief screening tool, offer advantages in resource-constrained settings.

Objective: To assess the validity/reliability of PHQ-9 and PHQ-2.

Design: Observational, two occasions 7 days apart.

Participants: A total of 347 patients attending psychosocial support groups.

Measurements: Demographics, PHQ-9, PHQ-2, general health perception rating and CD4 count.

Results: Rates for PHQ-9 DSM-IV major depressive disorder (MDD), other depressive disorder (ODD) and any depressive disorder were 13%, 21% and 34%. Depression was associated with female gender, but not CD4. Construct validity was supported by: (1) a strong association between PHQ-9 and general health rating, (2) a single major factor with loadings exceeding 0.50, (3) item-total correlations exceeding 0.37 and (4) a pattern of item means similar to US validation studies. Four focus groups indicated culturally relevant content validity and minor modifications to the PHQ-9 instructions. Coefficient alpha was 0.78. Test-retest reliability was acceptable: (1) intraclass correlation 0.59 for PHQ-9 total score, (2) kappas 0.24, 0.25 and 0.38 for PHQ-9 MDD, ODD and any depressive disorder and (3) weighted kappa 0.53 for PHQ-9 depression severity categories. PHQ-2 > or =3 demonstrated high sensitivity (85%) and specificity (95%) for diagnosing any PHQ-9 depressive disorder (AUC, 0.97), and 91% and 77%, respectively, for diagnosing PHQ-9 MDD (AUC, 0.91). Psychometrics were also good within four gender/age (18-35, 36-61) subgroups.

Conclusions: PHQ-9 and PHQ-2 appear valid/reliable for assessing DSM-IV depressive disorders and depression severity among adults living with HIV/AIDS in western Kenya.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Validation Study

MeSH terms

  • Acquired Immunodeficiency Syndrome / complications
  • Acquired Immunodeficiency Syndrome / diagnosis*
  • Acquired Immunodeficiency Syndrome / epidemiology
  • Acquired Immunodeficiency Syndrome / psychology*
  • Adolescent
  • Adult
  • Depressive Disorder / complications
  • Depressive Disorder / diagnosis*
  • Depressive Disorder / epidemiology
  • Depressive Disorder / psychology*
  • Female
  • HIV Infections / complications
  • HIV Infections / diagnosis
  • HIV Infections / epidemiology
  • HIV Infections / psychology
  • Humans
  • Kenya / epidemiology
  • Male
  • Middle Aged
  • Neuropsychological Tests / standards
  • Psychiatric Status Rating Scales / standards*
  • Severity of Illness Index
  • Young Adult