[The opening of the French national health database: Opportunities and difficulties. The experience of the Gazel and Constances cohorts]. / L'ouverture du Système national d'information inter-régimes de l'assurance maladie (SNIIRAM) : des opportunités et des difficultés. L'expérience des cohortes Gazel et Constances.

BACKGROUND: In France, the national health database (SNIIRAM) is an administrative health database that collects data on hospitalizations and healthcare consumption for more than 60 million people. Although it does not record behavioral and environmental data, these data have a major interest for epidemiology, surveillance and public health. One of the most interesting uses of SNIIRAM is its linkage with surveys collecting data directly from persons. Access to the SNIIRAM data is currently relatively limited, but in the near future changes in regulations will largely facilitate open access. However, it is a huge and complex database and there are some important methodological and technical difficulties for using it due to its volume and architecture. METHODS: We are developing tools for facilitating the linkage of the Gazel and Constances cohorts to the SNIIRAM: interactive documentation on the SNIIRAM database, software for the verification of the completeness and validity of the data received from the SNIIRAM, methods for constructing indicators from the raw data in order to flag the presence of certain events (specific diagnosis, procedure, drug…), standard queries for producing a set of variables on a specific area (drugs, diagnoses during a hospital stay…). Moreover, the REDSIAM network recently set up aims to develop, evaluate and make available algorithms to identify pathologies in SNIIRAM. CONCLUSION: In order to fully benefit from the exceptional potential of the SNIIRAM database, it is essential to develop tools to facilitate its use.