[Linking of individual data. Methods of linkage]

This paper gives an overview of linking methods of personal data computed in different files as registers and administrative or medical records. Epidemiological and demographic examples are studied, then the successive steps of record linkage are described:definition and choice of identifiants, searching and comparing pairs of records to determine whether they should be linked. A special mention is made to probability matching and methods optimizing the matching procedures. The discussion envisages the advantages of record linkage:better use of health statistics, new types of epidemiologic studies. The ethical problems and the need for evaluation are also discussed.