East Coast Ballroom
Population-based registry linkages to improve the validity of electronic health record-based cancer research (307939)
*Caroline Thompson, San Diego State UniversityLaura Allen, University of California San Francisco
Scarlett Gomez, University of California San Francisco
Anqi Jin, Sutter Health Palo Alto Medical Foundation Research Institute
Su-Ying Liang, Sutter Health Palo Alto Medical Foundation Research Institute
Daphne Y. Lichtensztajn, University of California San Francisco
Harold S. Luft, Sutter Health Palo Alto Medical Foundation Research Institute
Benjamin Schumacher, San Diego State University
There is tremendous potential to leverage the value gained from integrating electronic health records (EHRs) and population-based cancer registry data to study the cancer continuum. A carefully conducted cancer registry linkage may also be used to inform and improve the validity of inference from an EHR-based analysis.We linked the EHRs of a large, multispecialty, mixed-payer healthcare system with the statewide cancer registry and assessed the internal and external validity of our linked population. For internal validity, we identify patients that might be “missed” in a linkage, threatening the internal validity of an EHR study population. For external validity, we compared linked cases with all other cancer patients in the 22-county EHR catchment region. From an EHR population of 4.5M, we identified 306,554 cancer patients, 26% of the catchment regions cancer patients. 22.7% of linked patients were diagnosed with cancer after they migrated away from our healthcare system. We observed marked demographic differences between EHR patients and non-EHR patients in the catchment region and demonstrated use of inverse probability of selection with model-based standardization to improve generalizability of our EHR cohort to the source population. Researchers conducting linkages may benefit from considering one or more of these approaches to establish and evaluate the validity of their EHR-based populations.