The Manitoba Centre for Health Policy (MCHP) has been called a "data-rich environment" (Roos et al. 2004). Indeed, the depth and breadth of the data justify this description – there are currently nearly 100 databases held in the Population Health Data Repository ("the Repository") at MCHP, with some containing data back to 1970. And the number of databases continues to grow. However, it is not merely the volume of data that is important – rather, it is the synergy that is created when these databases are linked. Every data set at MCHP can be linked to others through a longitudinal registry of virtually every resident of Manitoba. This comprehensiveness presents unique research opportunities that would not be possible otherwise. All personal identifiers are removed, and the Personal Health Identifier Number (PHIN) that is used to link all databases is scrambled to protect individual privacy. In addition, strict access control and approval processes are in place.