Patient Health Questionnaire-9 scores do not accurately estimate depression prevalence: individual participant data meta-analysis

Brooke Levis, Andrea Benedetti, John P.A. Ioannidis, Ying Sun, Zelalem Negeri, Chen He, Yin Wu, Ankur Krishnan, Parash Mani Bhandari, Dipika Neupane, Mahrukh Imran, Danielle B. Rice, Kira E. Riehm, Nazanin Saadat, Marleine Azar, Jill Boruff, Pim Cuijpers, Simon Gilbody, Lorie A. Kloda, Dean McMillanScott B. Patten, Ian Shrier, Roy C. Ziegelstein, Sultan H. Alamri, Dagmar Amtmann, Liat Ayalon, Hamid R. Baradaran, Anna Beraldi, Charles N. Bernstein, Arvin Bhana, Charles H. Bombardier, Gregory Carter, Marcos H. Chagas, Dixon Chibanda, Kerrie Clover, Yeates Conwell, Crisanto Diez-Quevedo, Jesse R. Fann, Felix H. Fischer, Leila Gholizadeh, Lorna J. Gibson, Eric P. Green, Catherine G. Greeno, Brian J. Hall, Emily E. Haroz, Khalida Ismail, Nathalie Jetté, Mohammad E. Khamseh, Yunxin Kwan, Maria Asunción Lara, Shen Ing Liu, Sonia R. Loureiro, Bernd Löwe, Ruth Ann Marrie, Laura Marsh, Anthony McGuire, Kumiko Muramatsu, Laura Navarrete, Flávia L. Osório, Inge Petersen, Angelo Picardi, Stephanie L. Pugh, Terence J. Quinn, Alasdair G. Rooney, Eileen H. Shinn, Abbey Sidebottom, Lena Spangenberg, Pei Lin Lynnette Tan, Martin Taylor-Rowan, Alyna Turner, Henk C. van Weert, Paul A. Vöhringer, Lynne I. Wagner, Jennifer White, Kirsty Winkley, Brett D. Thombs

Research output: Contribution to journalArticlepeer-review

113 Scopus citations


Objectives: Depression symptom questionnaires are not for diagnostic classification. Patient Health Questionnaire-9 (PHQ-9) scores ≥10 are nonetheless often used to estimate depression prevalence. We compared PHQ-9 ≥10 prevalence to Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders (SCID) major depression prevalence and assessed whether an alternative PHQ-9 cutoff could more accurately estimate prevalence. Study Design and Setting: Individual participant data meta-analysis of datasets comparing PHQ-9 scores to SCID major depression status. Results: A total of 9,242 participants (1,389 SCID major depression cases) from 44 primary studies were included. Pooled PHQ-9 ≥10 prevalence was 24.6% (95% confidence interval [CI]: 20.8%, 28.9%); pooled SCID major depression prevalence was 12.1% (95% CI: 9.6%, 15.2%); and pooled difference was 11.9% (95% CI: 9.3%, 14.6%). The mean study-level PHQ-9 ≥10 to SCID-based prevalence ratio was 2.5 times. PHQ-9 ≥14 and the PHQ-9 diagnostic algorithm provided prevalence closest to SCID major depression prevalence, but study-level prevalence differed from SCID-based prevalence by an average absolute difference of 4.8% for PHQ-9 ≥14 (95% prediction interval: −13.6%, 14.5%) and 5.6% for the PHQ-9 diagnostic algorithm (95% prediction interval: −16.4%, 15.0%). Conclusion: PHQ-9 ≥10 substantially overestimates depression prevalence. There is too much heterogeneity to correct statistically in individual studies.

Original languageEnglish
Pages (from-to)115-128.e1
JournalJournal of Clinical Epidemiology
StatePublished - Jun 2020

Bibliographical note

Publisher Copyright:
© 2020 Elsevier Inc.


FundersFunder number
Medical Research CouncilMR/J000914/1


    • Depression prevalence
    • Individual participant data meta-analysis
    • PHQ-9
    • SCID


    Dive into the research topics of 'Patient Health Questionnaire-9 scores do not accurately estimate depression prevalence: individual participant data meta-analysis'. Together they form a unique fingerprint.

    Cite this