[Individual registration of children in the national health service. New possibilities for epidemiological research in primary health care].

Since January 1st 1996 all Danish citizens, children included, have been recorded individually in The National Health Service Register (SSR). Services rendered to children are no longer registered with an adult person. This article describes the implementation of this new arrangement. The part of health services to children recorded under an adult personal identification number is getting asymptotically closer to a minimum of about four percent, which is determined by the average time of naming of children. After the introduction of individual registration of children the SSR has improved considerably as a basis for epidemiological studies in Danish primary care.