How do the PHQ-2, the PHQ-9 perform in aging services clients with cognitive impairment?

To examine the performance of the Patient Health Questionnaire-2 (PHQ-2) and the PHQ-9 in detecting current major depressive episode (MDE) in aging services care management clients who screen positive for cognitive impairment (CI).

Cross-sectional observational study of 236 care management clients ages ≥60 years recruited from an Upstate NY aging services agency. The test characteristics of the PHQ-2 and PHQ-9 to screen for depression were calculated using the Structured Clinical Interview for DSM-IV (SCID) to identify MDE (gold standard). CI was identified with the Six-Item Screen (SIS).

Participants had a mean age of 77 years, 68% female, 16% non-white, and 26% had less than a high school education. 16% of participants had CI identified by ≥2 errors on SIS. Of these, 41% had positive PHQ-2 (scores ≥3), 43% had positive PHQ-9 (scores ≥10), while 24% met criteria for MDE. In the sample with CI, the PHQ-2, using a cutoff of 3, had sensitivity = 0.78, specificity = 0.71, and receiver operating characteristic (ROC) area under the curve (AUC) = 0.81, compared with 0.79, 0.82, and 0.88, respectively, for those without CI. In the sample with CI, the PHQ-9, using a cutoff of 10, had sensitivity = 0.89, specificity = 0.71, and AUC = 0.85, compared with 0.85, 0.89, and 0.91, respectively, for those without CI.

Cognitive status should be considered when using the PHQ as a depression screener due to poorer specificity in seniors with CI.