Administrative data linkage
Connect routine records across systems
Administrative data are generated through services, transactions or organisational operations rather than primarily for research. Linkage joins records about the same people or entities across systems or periods, using approved identifiers or probabilistic matching. It can reveal long-term outcomes, but operational definitions, linkage error, changing coverage and privacy controls are central methodological issues.
Use when routinely recorded outcomes and approved linkage can answer the question at meaningful scale. Confirm access routes early, since secure-environment approvals and linkage arrangements can dominate project duration.
Strengths
- Connects outcomes over long periods without participant recall
- Can cover large service populations
Limitations
- Linkage failures may differ systematically between groups
- Operational records often omit important confounders
Know the boundary
Large administrative datasets do not remove selection bias or create causal identification by themselves.