Sensitivity and specificity of the Distress Thermometer and a two-item depression screen (Patient Health Questionnaire-2) with a 'help' question for psychological distress and psychiatric morbidity in patients with advanced cancer

Abstract

Objectives: Brief screening tools may help clinicians in busy settings detect patients who are experiencing severe psychological distress. This study examined the performance of the Distress Thermometer (DT) and a two-item depression screen [the Patient Health Questionnaire-2 (PHQ-2)] with a 'help' question in screening for distress and psychiatric morbidity among patients with advanced cancer.

Methods: Two hundred and five patients with advanced cancer completed the DT, the PHQ-2 and 'help' question and the Hospital Anxiety and Depression Scale and were interviewed using the Structured Clinical Interview for DSM-IV (SCID). The performance of the screening tools was examined against the Hospital Anxiety and Depression Scale and the SCID.

Results: Overall, discrimination levels were comparable for the DT [area under the curve (AUC) 0.80-0.81] and the PHQ-2 (AUC 0.73-0.85). The DT performed best in detecting cases of distress and mood, anxiety or adjustment disorders (sensitivity 100%), but it had poor specificity (49-60%). The best performance in terms of combined sensitivity and specificity was the PHQ depression item versus the SCID (sensitivity 88%, specificity 73%). The inclusion of the 'help' question with the PHQ-2 resulted in high levels of specificity (≥89%), but there was a significant drop in sensitivity (≤54%).

Conclusion: Ultra-brief screening tools offer an efficient means of identifying patients with advanced cancer with severe distress or psychiatric morbidity but are less effective at identifying non-distressed individuals. Used in conjunction with a 'help' question, these tools can help clinicians identify patients who are both distressed and likely to accept professional support.