Equivalency of the diagnostic accuracy of the PHQ-8 and PHQ-9: a systematic review and individual participant data meta-analysis

• Published in: Psychological medicine Vol. 50; no. 8; pp. 1368 - 1380
• Main Authors: Wu, Yin, Levis, Brooke, Riehm, Kira E., Saadat, Nazanin, Levis, Alexander W., Azar, Marleine, Rice, Danielle B., Boruff, Jill, Cuijpers, Pim, Gilbody, Simon, Ioannidis, John P.A., Kloda, Lorie A., McMillan, Dean, Patten, Scott B., Shrier, Ian, Ziegelstein, Roy C., Akena, Dickens H., Arroll, Bruce, Ayalon, Liat, Baradaran, Hamid R., Baron, Murray, Bombardier, Charles H., Butterworth, Peter, Carter, Gregory, Chagas, Marcos H., Chan, Juliana C. N., Cholera, Rushina, Conwell, Yeates, de Man-van Ginkel, Janneke M., Fann, Jesse R., Fischer, Felix H., Fung, Daniel, Gelaye, Bizu, Goodyear-Smith, Felicity, Greeno, Catherine G., Hall, Brian J., Harrison, Patricia A., Härter, Martin, Hegerl, Ulrich, Hides, Leanne, Hobfoll, Stevan E., Hudson, Marie, Hyphantis, Thomas, Inagaki, Masatoshi, Jetté, Nathalie, Khamseh, Mohammad E., Kiely, Kim M., Kwan, Yunxin, Lamers, Femke, Liu, Shen-Ing, Lotrakul, Manote, Loureiro, Sonia R., Löwe, Bernd, McGuire, Anthony, Mohd-Sidik, Sherina, Munhoz, Tiago N., Muramatsu, Kumiko, Osório, Flávia L., Patel, Vikram, Pence, Brian W., Persoons, Philippe, Picardi, Angelo, Reuter, Katrin, Rooney, Alasdair G., Santos, Iná S., Shaaban, Juwita, Sidebottom, Abbey, Simning, Adam, Stafford, Lesley, Sung, Sharon, Tan, Pei Lin Lynnette, Turner, Alyna, van Weert, Henk C., White, Jennifer, Whooley, Mary A., Winkley, Kirsty, Yamada, Mitsuhiko, Benedetti, Andrea, Thombs, Brett D.
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.06.2020
• Subjects: Accuracy; Cardiovascular disease; Citation management software; Coronary vessels; Datasets; Depressive Disorder, Major - classification; Depressive Disorder, Major - diagnosis; Female; Humans; Interviews; Interviews as Topic; Male; Mass Screening - methods; Medical diagnosis; Medical screening; Mental depression; Mental disorders; Meta-analysis; Middle Aged; Original Articles; Patient Health Questionnaire; Primary care; Risk assessment; Self destructive behavior; Self injury; Sensitivity and Specificity; Suicide; Suicides & suicide attempts; Systematic review; United States > US; diagnostic accuracy; screening; individual participant data meta-analysis; meta-analysis; Depression; PHQ-9; systematic review; PHQ-8
• ISSN: 0033-2917; 1469-8978; 1469-8978
• DOI: 10.1017/S0033291719001314

Item 9 of the Patient Health Questionnaire-9 (PHQ-9) queries about thoughts of death and self-harm, but not suicidality. Although it is sometimes used to assess suicide risk, most positive responses are not associated with suicidality. The PHQ-8, which omits Item 9, is thus increasingly used in research. We assessed equivalency of total score correlations and the diagnostic accuracy to detect major depression of the PHQ-8 and PHQ-9. We conducted an individual patient data meta-analysis. We fit bivariate random-effects models to assess diagnostic accuracy. 16 742 participants (2097 major depression cases) from 54 studies were included. The correlation between PHQ-8 and PHQ-9 scores was 0.996 (95% confidence interval 0.996 to 0.996). The standard cutoff score of 10 for the PHQ-9 maximized sensitivity + specificity for the PHQ-8 among studies that used a semi-structured diagnostic interview reference standard (N = 27). At cutoff 10, the PHQ-8 was less sensitive by 0.02 (-0.06 to 0.00) and more specific by 0.01 (0.00 to 0.01) among those studies (N = 27), with similar results for studies that used other types of interviews (N = 27). For all 54 primary studies combined, across all cutoffs, the PHQ-8 was less sensitive than the PHQ-9 by 0.00 to 0.05 (0.03 at cutoff 10), and specificity was within 0.01 for all cutoffs (0.00 to 0.01). PHQ-8 and PHQ-9 total scores were similar. Sensitivity may be minimally reduced with the PHQ-8, but specificity is similar.