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

Abstract

BackgroundItem 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.MethodsWe conducted an individual patient data meta-analysis. We fit bivariate random-effects models to assess diagnostic accuracy.Results16 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).ConclusionsPHQ-8 and PHQ-9 total scores were similar. Sensitivity may be minimally reduced with the PHQ-8, but specificity is similar.

Probability of Major Depression Classification Based on the SCID, CIDI, and MINI Diagnostic Interviews: A Synthesis of Three Individual Participant Data Meta-Analyses

“…Differences in classifying participants could similarly reduce the ability to identify potential associations between risk factors and depression. In studies of diagnostic test accuracy, the accuracy of the depression screening tool has been shown to differ across reference standards [33,41,42]. In studies of major depression prevalence, the MINI tends to overestimate compared to the SCID whereas with the CIDI, relative prevalence will depend on the underlying distribution of depressive symptoms.…”

Validation of the COVID-19 Fears Questionnaires for Chronic Medical Conditions: A Scleroderma Patient-centered Intervention Network COVID-19 Cohort study

“…The 8-item Patient Health Questionnaire (PHQ-8) [ 26 ] measures depressive symptoms over the last 2 weeks on a 4-point scale, ranging from 0 (not at all) to 3 (nearly every day) with higher scores (range 0 to 24) indicating more depressive symptoms. The PHQ-8 performs equivalently to the PHQ-9 [ 27 ], which is a valid measure of depressive symptoms in patients with SSc [ 28 ]. The PHQ-8 is available in English and French [ 29 ].…”

Psychometric Analysis and Factor Structure of the Spanish Version of the Eight-Item Patient Health Questionnaire in a General Sample of Puerto Rican Adults

“…Thus, there is no significant difference between PHQ-8 and PHQ-9 versions to discriminate the depressive symptoms (Alpizar, Plunkett, & Whaling, 2018). Wu et al (2019) conducted an individual patient data meta-analysis with 16,742 participants from 54 selected studies. The meta-analysis revealed that the correlation between PHQ-8 and PHQ-9 scores was .996 (95% confidence interval, [0.996, 0.996]).…”