Simplifying record linkage: software and strategy.

Although the methodology of record linkage is fairly well developed, there is a need for less expensive methods and simpler software to facilitate trying out different tactics to generate good linkages. The present work has built on a fourth generation language SAS (Statistical Analysis System) with accompanying macroprocessor, to develop a user-friendly and flexible system for both exact and probabilistic matching. The major features of the LINKS system are presented and illustrated using 1979-1984 information from the Manitoba Health Services Commission (MHSC) registry file with the Canadian Mortality Data Base. Initial runs with exact, then probabilistic, matching linked approximately 91% of the Vital Statistics records to corresponding MHSC records. Subsequent modification of parameters improved the linkage to 95%.