FIGURE 4.4d Exposed population from a nuclear power plant crossing state boundaries.
Massachusetts, and Maine. This has the potential to create logistical challenges in access to state-level administrative and health outcome data.
4.3.2 Cancer Registration Data
In theory, a cancer registry includes all cases of cancer in a defined population over a defined time period (such as all cases with a diagnosis after January 1, 1990). In practice there is always a cutoff date as well (such as diagnosis before January 1, 2009). Registries also have rules about what constitutes date of diagnosis to deal with such problems as a clinical suspicion of cancer, followed by an imaging study, followed by a positive biopsy. Such information is needed for any incidence- or mortality-based ecologic study, any cohort study that compares cancer rates in different areas, or a case-control study that estimates associations.
It takes time, typically 1-2 years after the occurrence of the cancer, to get registry files that are virtually complete. Connecticut was the first state