A probabilistic and interactive decision-analysis system for unruptured intracranial aneurysms.

Object: The goal in this study was to develop an interactive, probabilistic decision-analysis system for clinical use in the decision to treat or observe unruptured intracranial aneurysms. Further goals were to enable users of the system to adapt decision-analysis methods to individual patients and to provide a tool for interactive sensitivity analysis.

Methods: A computer program was designed to model the outcomes of treatment and observation of unruptured aneurysms. The user supplies probabilistic estimates of key parameters relating to a specific patient and nominates discount rate and quality of life adjustments. The program uses Monte Carlo discrete-event simulation methods to derive probability estimates of the outcomes of treatment and observation. Results are expressed as summary statistics and graphs. Discounted quality-adjusted life years are graphed using survival methods. Hierarchical simulations are used to enable investigators to perform probabilistic sensitivity analysis for one or multiple parameters simultaneously. The results of sensitivity analysis are expressed in graphs and as the expected value of perfect information. The system can be distributed and updated using the Internet.

Conclusions: Further research is required into the benefits of clinical application of this system. Further research is also required into the optimum level of complexity of the model, into the user interface, and into how clinicians and patients are likely to interpret results. The system is easily adaptable to a range of medical decision analyses.