The PRCDA data item is derived using NAACCR*Prep based on the state and county at the time of diagnosis according to the definition in the April 7, 2016,
Federal Register.
Data analyses restricted to areas with health care services provided by the Indian Health Service (IHS) improve the accuracy of American Indian/Alaska Native (AI/AN) cancer statistics. IHS Purchased/Referred Care Delivery Areas (PRCDA) consist of counties which include all or part of an AI/AN reservation and any county or counties which have a common boundary with a reservation. This derived data item facilitates the production of the most accurate and reliable incidence rates for the American Indian/Alaskan Native population and was previously known as IHS Contract Health Service Delivery Area (CHSDA).