Measurement invariance of the patient health questionnaire-9 (PHQ-9) depression screener in U.S. adults across sex, race/ethnicity, and education level: NHANES 2005–2016

Jay S. Patel, Youngha Oh, Kevin L. Rand, Wei Wu, Melissa A. Cyders, Kurt Kroenke, Jesse C. Stewart

Research output: Contribution to journalArticle

1 Scopus citations


Background: Despite its popularity, little is known about the measurement invariance of the Patient Health Questionnaire-9 (PHQ-9) across U.S. sociodemographic groups. Use of a screener shown not to possess measurement invariance could result in under/over-detection of depression, potentially exacerbating sociodemographic disparities in depression. Therefore, we assessed the factor structure and measurement invariance of the PHQ-9 across major U.S. sociodemographic groups. Methods: U.S. population representative data came from the 2005–2016 National Health and Nutrition Examination Survey (NHANES) cohorts. We conducted a measurement invariance analysis of 31,366 respondents across sociodemographic factors of sex, race/ethnicity, and education level. Results: Considering results of single-group confirmatory factor analyses (CFAs), depression theory, and research utility, we justify a two-factor structure for the PHQ-9 consisting of a cognitive/affective factor and a somatic factor (RMSEA = 0.034, TLI = 0.985, CFI = 0.989). On the basis of multiple-group CFAs testing configural, scalar, and strict factorial invariance, we determined that invariance held for sex, race/ethnicity, and education level groups, as all models demonstrated close model fit (RMSEA = 0.025–0.025, TLI = 0.985–0.992, CFI = 0.986–0.991). Finally, for all steps ΔCFI was <−0.004, and ΔRMSEA was <0.01. Conclusions: We demonstrate that the PHQ-9 is acceptable to use in major U.S. sociodemographic groups and allows for meaningful comparisons in total, cognitive/affective, and somatic depressive symptoms across these groups, extending its use to the community. This knowledge is timely as medicine moves towards alternative payment models emphasizing high-quality and cost-efficient care, which will likely incentivize behavioral and population health efforts. We also provide a consistent, evidence-based approach for calculating PHQ-9 subscale scores.

Original languageEnglish (US)
Pages (from-to)813-823
Number of pages11
JournalDepression and anxiety
Issue number9
StatePublished - Sep 1 2019



  • depression
  • epidemiology
  • health services
  • measurement/psychometrics
  • minority groups
  • treatment

ASJC Scopus subject areas

  • Clinical Psychology
  • Psychiatry and Mental health

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