Pain measurement tools and methods in clinical research in palliative care: recommendations of an Expert Working Group of the European Association of Palliative Care.

An Expert Working Group was convened under the auspices of the Steering Committee of the Research Network of the European Association of Palliative Care to review the status of the use of pain measurement tools (PMTs) in palliative care research conducted in a multilingual-multicenter setting. Based on a literature review and on the experts' opinion, the present work recommends that standardized methods should be applied for the use of PMTs in research in palliative care. Visual analogue scales, numerical rating scales, and verbal rating scales are considered valid to assess pain intensity in clinical trials and in other types of studies. Among the multidimensional questionnaires designed to assess pain, the McGill Pain Questionnaire and Brief Pain Inventory are valid in many multilingual versions. Specific recommendations for PMT use and administration, depending on the study type and aim, are reviewed. Special population requirements specific of clinical situations encountered in palliative care (elderly, terminal, cognitively impaired patients, pediatric patients) are also considered.