Postmarketing surveillance with computer-based patient records.

Postmarketing Surveillance (PMS) concerns the investigation of side-effects of drugs after they are introduced into the market. Traditionally, data collection for PMS-studies has been paper-based. The increasing number of general practitioners (GP) that use Computer-Based Patient Records (CBPR) and the central role these general practitioners in the Netherlands play in the delivery of care makes the use of CBPRs as a resource of data for PMS studies possible. Analysis of the current available CBPRs, however, proved them insufficient for PMS studies, because too much data is available only in free text, and other necessary data for PMS is lacking. To make the CBPR suitable for PMS, we had to build a software-module that could be plugged into the computer system of the GP. The module checks the data immediately after they it has been entered into the system, and missing data is requested. Initial filed studies have shown that, with this module, the collection of PMS data is feasible.