Which of the following is a likely data source used in record linkage?

• A. Facility electronic health record
• B. Pathology laboratory
• C. Central registry
• D. All are valid data sources

Answer: (D)

Record linkage relies on bringing together records from multiple repositories that refer to the same person to build a more complete picture of their health events. A facility electronic health record provides detailed clinical encounters, treatments, and outcomes from a specific setting, but may miss data from other places the patient has been treated. A pathology laboratory contributes objective, disease-specific evidence (such as histology or cytology results) that can confirm a cancer diagnosis, which is essential for accurate case identification. A central registry collects standardized information from many sources over time and across institutions, helping to harmonize data and support population-wide linkage.

Because each source offers different pieces of the puzzle and has its own gaps, combining all of them increases the chances of correctly matching records to the same individual and yields a more complete, accurate dataset for surveillance or research. In practice, linkage uses identifiers like names, dates of birth, and patient IDs, with probabilistic or deterministic matching, while also considering privacy and governance.