By linkage of all individuals to these addresses using the unique Central Population Register (CPR) number (10-digit number in the Civil Registration System), the GIS eventually contained all the following information in addition to the addresses of each individual: date of birth, sex, migration (into, out of, and around the study area), and date of death.
Specific gene signatures for each individual population could also be developed using the unique cliques that were identified in each population.
We followed all participants through linkages with the Cancer Registry of Norway, the Norwegian Cause of Death Registry, and the Central Population Register using the unique 11-digit personal identification number to identify all cancer cases, deaths and emigrations.
We followed all participants through linkages to the Cancer Registry of Norway and the Central Population Register using the unique 11-digit personal identification number to identify all cancer cases, emigrations and deaths, respectively.
Women in the NOWAC study were linked to various population-based registries using the unique, 11-digit, national personal identification number.
Demographic data including gender, birth date, area of residence, marital status and number of children less than 15 years were obtained by linking Danish population-based registers using the unique personal identification number, assigned to all persons living in Denmark and used across all registration systems [ 19].
Using the unique Danish personal identification number, we retrieved and linked supplemental information from several large population-based registers [ 6].
Data from the population-based surveys were linked to nation-wide registers by using the unique personal identification number (CPR-number).
We used the unique opportunity of the premarital examinations to obtain population based data on reproductive need of women who were not yet married.
Using a unique population of TTTS survivors, we have identified subtle but potentially important variability in DNA methylation influenced by the physiologic environment during development.
