Acquiring an evidence base in palliative care: challenges and future directions.

Patients experiencing life-threatening illnesses deserve to receive palliative care services that are informed and driven by high-quality research findings. While there is an urgent need to establish a more substantial evidence base in palliative care, acquiring such evidence is replete with challenge. This special report outlines some of those challenges, highlights the limitations of extant taxonomies used to evaluate levels of empirically generated evidence and offers direction regarding alternative approaches to the generation and appraisal of palliative care research.