The epidemiological information system of the French national electricity and gas company: the SI-EPI project.

SI-EPI is epidemiological information system set up in 1978 in the national electricity and gas company, Electricité de France-Gaz de France (EDF-GDF). The worker population comprises about 150,000 individuals, involved in production, transmission and distribution of energy. SI-EPI was developed by the epidemiologists of the Occupational Health Department (180 physicians), and of the Sécurité Sociale Department (120 physicians). Several data bases constitute SI-EPI. The population data base contains demographic, socioeconomic and professional data about each worker. The health data base is an exhaustive register of sick leave, accidents, permanent disabilities, compensated diseases, causes of death and cancer incidence among active workers. The Occupational Exposure and Working Conditions data base includes the MATEX job-exposure matrix (30 potentially carcinogenic agents) and FINDEX files which record data obtained from the systematic individual surveillance of workers. The GAZEL cohort data base concerns a sample of more than 20,000 volunteer workers, followed since 1989; in addition to data from the data bases, it contains information collected from other different sources, including self-questionnaires. Numerous epidemiological studies based on SI-EPI data have been conducted by in-house epidemiologists as well as by external research groups. They include mortality and morbidity studies and address various topics and health problems. Their results are used for internal information, as well as for epidemiological research purposes.