In epidemiology the term 'register' is applied to the file of data concerning all cases of a particular disease or other health-relevant condition in a defined population such that the cases can be related to a population base. With this information, incidence rates can be calculated. If the cases are regularly followed up, information on remission, exacerbation, prevalence, and survival can also be obtained. The register is the actual document and the registry is the system of ongoing registration. 'Cancer registries' secure reports of cancer patients.
Source: Porta M. A
Dictionary of Epidemiology. 5th ed. New York, NY: Oxford
University Press; 2008.