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


METHODS
Observational, two occasions 7 days apart.


METHODS
A total of 347 patients attending psychosocial support groups.


METHODS
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.
Monahan
Patrick O
PO
Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202-3002, USA. pmonahan@iupui.edu
Shacham
Enbal
E
Reece
Michael
M
Kroenke
Kurt
K
Ong'or
Willis Owino
WO
Omollo
Otieno
O
Yebei
Violet Naanyu
VN
Ojwang
Claris
C
D000163:Acquired Immunodeficiency Syndrome / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology*; D000293:Adolescent; D000328:Adult; D003866:Depressive Disorder / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology*; D005260:Female; D015658:HIV Infections / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D006801:Humans; D007630:Kenya / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000592:standards; D011569:Psychiatric Status Rating Scales / Q000592:standards*; D012720:Severity of Illness Index; D055815:Young Adult