Rank-order stability analysis (ROSA): testing pharmacoeconomic data.

In a pharmacoeconomic analysis, the validity of findings is critical because product ranking may influence formulary decision making. The authors present an approach for examining uncertainty in a pharmacoeconomic analysis that parallels the confidence-interval approach to statistical analysis. This method, rank-order stability analysis (ROSA), is a clear and comprehensive method for validating results of a pharmacoeconomic analysis, as it identifies and evaluates all inputs and values. It is a break-even analysis that identifies the specific point of insensitivity for all parameters analyzed in the pharmacoeconomic model. ROSA is proposed as the preferred method for judging the validity of results derived from estimated parameters in pharmacoeconomic analyses.