We have shown that a simplified model, generated quickly in response to an emergency consultation, may provide useful insights in certain situations. A more developed model was useful in verifying these insights. Because the more complex model considered a longer time horizon than the simple model, it allows us to consider questions regarding long-term benefits of aneurysm repair. When modeling any problem, the most important reason for performing decision analysis is to gain insight from analyzing the clinical setting and from constructing the model. The quantitative results are usually of only minor importance. However, our most important insights are sometimes gained by looking beyond the quantitative level to understand the interactions of various effects within the model. In this case, it was those insights that were of the greatest benefit to the patient in arriving at a decision to have cerebral arteriography.