Decision analysis in the formulary process

The use of decision analysis as a tool in making formulary decisions is discussed. Decision analysis is best applied in formulary decisions when factors other than acquisition costs are important in determining overall treatment costs for two products. The decision-analysis process assigns probabilities and costs to various treatments and outcomes. In the case of acute myocardial infarction, the decision analyst would gather data on angioplasty and thrombolysis and assign probabilities and costs for each treatment and subsequent endpoints on the basis of clinical trial data. When such data do not exist, estimates may be generated by expert panels. Applying clinical trial data to an individual hospital is not straightforward because of differences between clinical trials and clinical practice. Analysts and clinicians should evaluate any proposed model for its robustness and adaptability to local conditions and practitioner variation. Access to internal hospital data is essential in developing the model. An ideal decision-analysis model includes all important available interventions and defines and discloses the analyst's time frame and financial perspective. After implementation of the formulary decision, the results can be monitored and, if necessary, adjustments can be made in the allocation of resources. Barriers to effective decision analysis include lack of data and differences in sources of cost and outcome data. Despite the current limitations of decision analysis, clinicians and policymakers may find this technique increasingly useful in the complex formulary process.