How does the Distress Thermometer compare to the Hospital Anxiety and Depression Scale for detecting possible cases of psychological morbidity among cancer survivors?

PURPOSE: Use of the Distress Thermometer (DT) as a screening tool is increasing across the cancer trajectory. This study examined the accuracy and optimal cut-off score of the DT compared to the Hospital Anxiety and Depression Scale (HADS) for detecting possible cases of psychological morbidity among adults in early survivorship.
METHODS: This study is a cross-sectional survey of 1,323 adult cancer survivors recruited from two state-based cancer registries in Australia. Participants completed the DT and the HADS at 6 months post-diagnosis.
RESULTS: Compared to the HADS subscale threshold ≥8, the DT performed well in discriminating between cases and non-cases of anxiety, depression and comorbid anxiety-depression with an area under the curve of 0.85, 0.84 and 0.87, respectively. A DT cut-off score of ≥2 was best for clinical use (sensitivity, 87-95 %; specificity, 60-68 %), ≥4 was best for research use (sensitivity, 67-82 %; specificity, 81-88 %) and ≥3 was the best balance between sensitivity (77-88 %) and specificity (72-79 %) for detecting cases of anxiety, depression and comorbid anxiety-depression. The DT demonstrated a high level of precision in identifying non-cases of psychological morbidity at all possible thresholds (negative predictive value, 77-99 %).
CONCLUSIONS: The recommended DT cut-off score of ≥4 was not supported for universal use among recent cancer survivors. The optimal DT threshold depends upon whether the tool is being used in the clinical or research setting. The DT may best serve to initially identify non-cases as part of a two-stage screening process. The performance of the DT against 'gold standard' clinical interview should be evaluated with cancer survivors.