SNDS

SNDS, or Système National des Données de Santé, is a national health data system in France that collects, links, and stores individual-level health information to support public health research and health policy. It integrates data from multiple sources to enable longitudinal analyses of health care utilization, diagnoses, procedures, medications, and outcomes.

The system draws primarily on the Système National d’Information Inter Régimes d’Assurance Maladie (SNIIRAM), which records reimbursed health care expenditures; the Programme de médicalisation des systèmes d’information (PMSI), which covers hospital discharge data; and national mortality and demographic data provided by INSEE. By linking these sources at the individual level, SNDS provides a comprehensive view of health care pathways for residents of France. The data are stored in de-identified or pseudonymized form to protect privacy, and a research-friendly subset, the Echantillon Généraliste des Bénéficiaires (EGB), comprises about one in a thousand individuals and is widely used for epidemiological and health economics studies.

Access and governance are strictly regulated. Researchers must obtain approval from relevant authorities and submit detailed project proposals, with oversight by CNIL and adherence to French data protection laws. Access is provided through secure environments, and data use agreements govern the handling and sharing of findings. Personal identifiers are removed or protected to minimize re-identification risk.

Use and impact: SNDS supports a broad range of studies in health services research, pharmacovigilance, and policy evaluation, informing understanding of disease patterns, treatment practices, medication safety, and health system performance. Limitations include coding variability and incomplete capture of certain conditions or care episodes.

See also: SNIIRAM, PMSI, INSEE, CNIL.