The study, led by Dr. Khaled El Emam of the Children's Hospital of Eastern Ontario, found information on drug prescriptions is a highly sought after commodity by pharmaceutical companies, which use the information in their marketing and sales efforts.
Emam said many retail pharmacies in Canada sell prescription records to commercial data aggregators who perform analyses for the pharmaceutical companies. The potential privacy risk in such a practice, the researchers said, is if the patients can be re-identified from this data.
The study, Emam said, demonstrates a methodology for deciding which data to keep and which to de-identify, since hospital prescription data contains details such as where patients live and when they were admitted to the hospital.
The risk analysis performed in the study outlines a way to maintain patients' privacy by generalizing and removing some variables, such as postal codes, gender and admission and discharge dates before they are shared with outside companies.
The research was reported in the July-August issue of the Canadian Journal of Hospital Pharmacy.