Beyond Claims: Dutch and Nordic Linked Data as European References for Precision Endpoints and High Impact Real-World Decisions

Real‑world data (RWD) sources vary widely in structure, coverage, and accessibility. In many large healthcare systems, including the US, France, Germany, and the UK, claims databases are the most readily accessible RWD resources. These datasets often have broad national coverage and capture coded information on healthcare utilization, diagnoses, procedures, and prescriptions, making them indispensable for large‑scale pharmacoepidemiologic research. For certain study types, however, particularly in rare diseases, precision medicine, or analyses requiring highly granular endpoints such as laboratory values, biomarker results, or staging, complementary data sources in other European countries with richer clinical detail can be advantageous.

Register‑based, multi‑setting linked datasets can address these needs by integrating information from hospitals, primary care, pharmacies, and other domains at the patient level. Multi setting datasets can be particularly valuable for research questions that require capturing the full patient journey across care environments, or for ensuring robust evidence transportability in complex disease areas, supporting complex analyses that single setting datasets may not fully enable.

Smaller European countries tend to “punch above their weight” in RWD because they can more realistically build coherent, national-scale data infrastructure: fewer payers and provider systems, more standardized administrative processes, and clearer nationwide governance make it feasible to maintain longitudinal, linkable datasets that follow patients across settings over time.

Two well-known examples of European reference ecosystems for linked, longitudinal real world evidence (RWE) are the PHARMO Data Network (Netherlands) and the national health registers in Denmark, Sweden, Norway, and Finland. These sources all provide longitudinal, patient‑level linkage across multiple healthcare settings to support complex study designs where clinically rich data has been needed. While they share many strengths, including multi‑domain coverage and the ability to link to external registries, each has distinctive operational and structural features.