Screening for major depression in cancer outpatients

Abstract

BACKGROUND: Systematic screening for depression has been recommended for patients who have medical conditions like cancer. The 9‐item Patient Health Questionnaire (PHQ‐9) is becoming widely used, but its diagnostic accuracy has not yet been tested in a cancer patient population. In this article, the authors report on the performance of the PHQ‐9 as a screening instrument for major depressive disorder (MDD) in patients with cancer. METHODS: Data obtained from a depression screening service for patients who were attending clinics of a Regional Cancer Centre in Edinburgh, United Kingdom were used. Patients had completed both the PHQ‐9 and a 2‐stage procedure to identify cases of MDD. Performance of the PHQ‐9 in identifying cases of MDD was determined using receiver operating characteristic (ROC) analysis. RESULTS: Data were available on 4264 patients. When scored as a continuous measure, the PHQ‐9 performed well with an area under the ROC curve of 0.94 (95% confidence interval [CI], 0.93‐0.95). A cutoff score of ≥8 provided a sensitivity of 93% (95% CI, 89%‐95%), a specificity of 81% (95% CI, 80%‐82%), a positive predictive value (PPV) of 25%, and a negative predictive value (NPV) of 99% and could be considered optimum in a screening context. The PHQ‐9 did not perform as well when it was scored using an algorithm with a sensitivity of 56% (95% CI, 55%‐57%), a specificity of 96% (95% CI, 95%‐97%), a PPV of 52%, and an NPV of 97%. CONCLUSIONS: The PHQ‐9 scored as a continuous measure with a cutoff score of ≥8 performed well in identifying MDD in cancer patients and should be considered as a screening instrument in this population. Cancer 2011. © 2010 American Cancer Society.