Use of routine healthcare data in safe and cost-effective drug use

Routine healthcare data is becoming widely available, usually as a result o f administrative systems. Other related data are also often available, such as biochemistry results, mortality data, and sometimes prescribing data. T hese records are often linked via a common identification system or by prob ability matching techniques. These data sources offer many opportunities to undertake research, and where prescription data are recorded and linked, t he facility to research the outcome of drug use often exists. There are now a number of research agencies around the world that use these large routin e data sources to undertake drug safety and outcome studies. The purpose of this commentary is to describe some of the history behind the development of these systems, illustrate some of their uses with respect to postmarketi ng drug safety and to other healthcare research objectives. The review then describes the data sources necessary to develop a system that would offer an optimal system to undertake a range of studies, including population dru g safety surveillance. There are both positive and negative considerations when using routine data. On the positive side, these data come from 'real l ife' experiences and not from the clinical trial situation. On the other ha nd, there are important biases to be aware of such as confounding by indica tion. On the whole, it is argued that large databases originating from rout ine healthcare procedures have an important role to play in the cost-effect ive prescription drug use in the postmarketing setting. These systems canno t replace other methods of drug safety evaluation but they do offer an impo rtant adjunct to spontaneous reporting systems.