Abstract:
Reliable record linkage is a prerequisite for high-quality population-based disease
registration. Rapid developments in computer processing have made record linkage both
more efficient and more reliable in recent years. At the same time, concerns about
confidentiality increasingly hinder record linkage in many disease registries. This
paper provides basic algebraic models describing the effects of record linkage errors
on monitoring disease incidence. Homonym errors, that is, erroneous linkage of records
that pertain to distinct individuals, lead to underestimation of incidence in the
registry population. The degree of underestimation strongly depends on the discriminating
power of personal identifiers and the record linkage procedure on the one hand, and
the number of registered cases on the other hand. Synonym errors, that is, failure
to link notifications on the same individual, lead to overestimation of incidence
in the population base. The combined effects of record linkage errors are illustrated
with empirical examples. We conclude that it is the largest and most informative disease
registries that are potentially affected most by impediments of record linkage procedures
due to unduly restrictive confidentiality rules.
Keywords
Disease Registries - Epidemiology - Incidence - Record Linkage