Security of healthcare data networks used for epidemiological studies

Record linkage, for compiling same-person records from various source files, can improve the feasibility of epidemiological research using population-based studies. The question is comply with the European legislation on data privacy and data security. For example, a computerized record hash coding and linkage procedure is described to link medical information within the framework of epidemiological follow-up, Before their extraction, files are rendered anonymous using a one-way hash coding based on the standard hash algorithm (SHA) function. Once rendered anonymous using using the software ANONYMAT, the linkage of patient information can be accomplished by means of a mixture model, taking into account several identification variables. An application of this anonymous record linkage procedure was carried out in order to link medical files on cancer, from 3 hospitals of the French Rhone-Alpes region, This application stresses how the use of the ANONYMAT software allows compliance with the legislation on data confidentiality without entailing problems oil data availability.