Psychiatry Investig.  2019 Apr;16(4):300-305. 10.30773/pi.2019.02.01.

Comparison of the Usefulness of the PHQ-8 and PHQ-9 for Screening for Major Depressive Disorder: Analysis of Psychiatric Outpatient Data

• Shin C
• Lee SH
• Han KM
• Yoon HK
• Han C

• KMID: 2447788
• DOI: http://doi.org/10.30773/pi.2019.02.01

Abstract

OBJECTIVE
This study aimed to demonstrate that the Patient Health Questionnaire (PHQ)-8 is not less useful than the PHQ-9 as a screening test for major depressive disorder (MDD).
METHODS
We performed a retrospective analysis of 567 patients in psychiatric outpatient units. The Mini International Neuropsychiatric Interview was used to diagnose MDD. We derived the validity and reliability of the PHQ-8 and PHQ-9. To evaluate the ability of the PHQ-8 and PHQ-9 to discriminate MDD, we drew receiver operating characteristic (ROC) curves and compared the areas under the curves (AUCs).
RESULTS
Of the 567 participants, 207 (36.5%) were diagnosed with MDD. Cronbach's αs for the PHQ-8 and PHQ-9 were 0.892 and 0.876, respectively. Similar to the PHQ-9, the PHQ-8 was also associated with scores on the Hamilton Depression Rating Scale in a correlation analysis. When we drew ROC curves for the PHQ-8 and PHQ-9, there was no statistically significant difference in the AUCs. With a cutoff score of 10, the PHQ-8 showed a sensitivity of 58.3%, specificity of 83.1%, positive predictive value of 53.4%, and negative predictive value of 85.7%.
CONCLUSION
In a psychiatric outpatient sample, the PHQ-8 was as useful as the PHQ-9 for MDD screening.

Keyword

Depression; Major depressive disorder; PHQ-8; PHQ-9

MeSH Terms

Area Under Curve
Depression
Depressive Disorder, Major*
Humans
Mass Screening*
Outpatients*
Reproducibility of Results
Retrospective Studies
ROC Curve
Sensitivity and Specificity