Using large-scale databases to measure outcomes in critical care.

The major intent of this article is to describe the availability and potential use of large-scale databases; however, it is first essential to know and understand the basic principles involved in the conduct and interpretation of observational outcomes studies. In this article, the authors briefly overview the design of observational outcomes studies as applied to critical care medicine. Then, criteria for evaluating data sources and for in-depth reviewing of the available data sources from which these observational studies can be conducted are discussed.