Research concerned with describing and explaining the occurrence of disease in populations.
The aims of epidemiological research are to: describe the health status of populations by enumerating the occurrence of diseases; obtain the relative frequencies within groups and identifying trends; explain the cause of diseases; predict the number of disease occurrence and distribution in a population; and control, prevent, and eradicate diseases, prolong life and improve health status.

In palliative care, epidemiological research has been hampered by the absence of clearly defining population indicators linked to the level of clinical needs, as well as changing perceptions within the profession of palliative care as to the appropriate ‘catchment population.’ The extended applications of palliative care from its original domain of terminally ill cancer patients to those with any life-limiting illness, and from the point of diagnosis onward, also pose problems.

Hanks G, Kaasa S, Forbes K. Research in Palliative Care. Hanks G, Cherny NI, Christakis NA, Fallon M, Kaasa S, Portenoy RK (Ed). Oxford Textbook of Palliative Medicine. Oxford University Press, 4th ed, 2010. pp.361-374.