Secure pseudonymisation for privacy-preserving probabilistic record linkage.

Record linkage is becoming an increasingly important tool in many areas of research – particularly medical research, where the relevant data often reside in more than one location. In the absence of a reliable and unique identifier probabilistic approaches to linkage are often employed. This linkage generally exploits the information contained in the fields that are common to a record pair. In classical record linkage the values in common fields are simply compared for equality. As values might contain typographical (or other) errors the performance of classical record linkage can often be significantly improved if similarities between value pairs are also exploited.