Inter-Registry deduplication activities and benefits
In addition to facilitating multi-registry cohort linkages, the VPR-CLS is committed to developing a secure mechanism to support inter-registry case de-duplication thereby improving the overall quality of cancer surveillance data. In a recent pilot test, Colorado and Idaho performed a linkage using hashed registry data. Hashed data allows registries to perform linkages on confidential data while that data is encrypted. The registries then met in person to perform a probabilistic linkage using their identifiable data, adjudicate the matches, and compare the results to the hashed linkage. This pilot linkage demonstrated proof-of-concept and identified areas for improvement in the process and the software. A second test of the system is being planned with multiple large registries.
The long-term goal is to perform inter-registry deduplication between all U.S. central registries which would provide the following benefits:
- Reduction in the number of duplicate case reports across state lines.
- More accurate estimates of cancer incidence.
- Sharing of information on mutual cases, thereby improving the accuracy and completeness of treatment and follow-up information.
- Identification of multiple primaries where a patient is diagnose with two different primaries in two different states.
- More accurate estimates of the incidence of multiple primaries.
