Decision analysis is a tool that uses an explicit, quantitative structure to describe and analyze complex health care decisions. This course will provide an introduction to the principles and practice of decision analysis. Upon completion of the course, participants will be able to evaluate the appropriateness of decision analysis in different settings, construct simple decision trees, understand the basic mechanics of tree evaluation and sensitivity analysis, and acquire skill in the interpretation of a published decision analysis. Extension of basic techniques, such as cost-effectiveness analysis and the assessment of patient preferences, will be briefly discussed. Class exercises will be used to illustrate these principles.