MANAGEMENT OF UNRUPTURED INTRACRANIAL ANEURYSM IN JAPAN - A MARKOVIANDECISION-ANALYSIS WITH UTILITY MEASUREMENTS BASED ON THE GLASGOW OUTCOME SCALE

The purpose of this study was to analyze the management of individual patients with unruptured intracranial aneurysms (UN-ANs) using a decis ion-analytic approach. Transition probabilities among Glasgow Outcome Scale (GOS) categories were estimated from the published literature an d data from patients who had been treated at Kitasato University Hospi tal. Utilities were obtained from 140 health providers based principal ly on the GOS. Baseline analysis for a healthy 40-year-old man with an anterior UN-AN less than 10 mm in diameter showed that the quality-ad justed life expectancies for preventive operation and follow-up were 1 5.34 and 14.66 years, respectively. For a follow-up strategy to be pre ferred, the annual rupture rate had to be as low as 0.9%. These result s were sustained through extensive sensitivity analysis. The results s upport preventive operation for UN-ANs, and identify problems that can be clarified with a well-designed stratified clinical trial.