The PHQ-9: validity of a brief depression severity measure.

Printer-friendly version
TitleThe PHQ-9: validity of a brief depression severity measure.
Publication TypeJournal Article
AuthorsKroenke K, Spitzer RL, Williams JB
Abbrev. JournalJ Gen Intern Med
JournalJournal of general internal medicine
Year of Publication2001
Volume16
Issue9
Pagination606-13
Publication Languageeng
KeywordsDepression, Questionnaires
Abstract

OBJECTIVE: While considerable attention has focused on improving the detection of depression, assessment of severity is also important in guiding treatment decisions. Therefore, we examined the validity of a brief, new measure of depression severity.

MEASUREMENTS: The Patient Health Questionnaire (PHQ) is a self-administered version of the PRIME-MD diagnostic instrument for common mental disorders. The PHQ-9 is the depression module, which scores each of the 9 DSM-IV criteria as "0" (not at all) to "3" (nearly every day). The PHQ-9 was completed by 6,000 patients in 8 primary care clinics and 7 obstetrics-gynecology clinics. Construct validity was assessed using the 20-item Short-Form General Health Survey, self-reported sick days and clinic visits, and symptom-related difficulty. Criterion validity was assessed against an independent structured mental health professional (MHP) interview in a sample of 580 patients.

RESULTS: As PHQ-9 depression severity increased, there was a substantial decrease in functional status on all 6 SF-20 subscales. Also, symptom-related difficulty, sick days, and health care utilization increased. Using the MHP reinterview as the criterion standard, a PHQ-9 score > or =10 had a sensitivity of 88% and a specificity of 88% for major depression. PHQ-9 scores of 5, 10, 15, and 20 represented mild, moderate, moderately severe, and severe depression, respectively. Results were similar in the primary care and obstetrics-gynecology samples.

CONCLUSION: In addition to making criteria-based diagnoses of depressive disorders, the PHQ-9 is also a reliable and valid measure of depression severity. These characteristics plus its brevity make the PHQ-9 a useful clinical and research tool.

PubMed URL

http://www.ncbi.nlm.nih.gov/pubmed/11556941?dopt=Abstract

Link to full texthttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC1495268/pdf/jgi_01114.pdf
PubMed Central IDPMC1495268

More resources on: