An analysis of the validity of the Hospital Anxiety and Depression scale as a screening tool in patients with advanced metastatic cancer.

Depression is difficult to diagnose in the terminally ill patient. As a result, it frequently is not treated. This has can have an adverse effect on quality of life and make the palliation of physical symptoms more difficult. In an effort to improve the detection of depression, many palliative care teams are using the Hospital Anxiety and Depression (HAD) scale as a screening tool. The HAD was devised for use in general medical settings and has not been validated for use in palliative care patients. One hundred patients receiving palliative care with an estimated prognosis of 6 months or less were invited to complete the HAD and a semi-structured psychiatric interview, the Present State Examination. The depression and anxiety subscales of the HAD showed poor efficacy for screening when used alone. The optimum threshold was at a combined cut-off of 19, which had a sensitivity of 68% and specificity of 67%. The major construct of the HAD is anhedonia, which may be present at the end of life due to increasing physical illness and may not be pathognomic of a depressive illness in this population. We recommend, therefore, that if the HAD is used as a screening tool in palliative care, it should be as a combined scale, but low sensitivity and specificity may lead to poor efficacy as a screening tool.