Privacy-Preserving Data Publishing for Free Text Chinese Electronic Medical Records

the practice of using electronic medical records (EMR) to store healthcare data instead of traditional paper is becoming popular, as it's widely believed that the efficiency of medical institution could be improved and the cost could be reduced by using EMR. Nevertheless, EMR makes the sensitive healthcare data much easier to collect, process, store and publish. The change has increased the privacy risk of patients significantly. There are still many problems about patients' privacy protection in practical application, although many methods have been proposed to handle privacy risk when using EMR. Many hospitals are trying to make use of accumulated free text EMR for medical research and training. However, the hospitals may lose control with the EMR as the EMR may be transferred to different organizations in such application. And properly dealing with patients' privacy in EMR is an important requirement to avoid privacy leakage in such applications. In this paper, we study the privacy protection challenge those Hospitals are facing when they try to share EMR with other institutions. Then, we identify the major problems that make the traditional privacy preserving methods not suitable to process free text EMR, especially for free text Chinese EMR. Furthermore, we propose a new method to solve the problems and design a privacy-preserving data publishing system for electronic medical records based on it. Experiments with real-life data is showed to evaluate the new method.