Background: Recent randomized clinical trials have shown that endovascular thrombectomy (EVT) improves 3 month disability outcomes in patients with acute ischemic stroke due to large vessel occlusion who present with large ischemic cores. However, moderate to fatal outcomes still predominate. The Utility Staircase display has been developed to provide a more granular delineation of utility-weighted modified Rankin Scale (UW-mRS) outcomes. The objective was to develop Utility Staircase displays for each of the major large core trials and for different large core volumes and compare these with displays for small-moderate core patients. Methods: In Utility Staircase displays, mRS segment height reflects the utility value of each mRS level and width reflects the proportion of patients at each mRS level. The area under the staircase then indicates the amount of value of the mRS outcomes for each treatment group. We developed Utility Staircase displays for each of the six major completed large core trials and for pooled trial data of outcomes for the three core volume size ranges of: 1) 70-99 cc; 2) 100-149 cc; and 3) ≥150 cc. Results: The Utility Staircase displays demonstrate that benefits are distributed across the utility space. The figures rapidly convey nuanced differences in the distributions of benefits in the utility space among these trials with similar numeric UW-mRS aggregate improvements. In 5 of the 6 trials, but not LASTE, there is accrual of benefit at each mRS utility step. The utility benefits cluster toward the lowest portion of the utility space for TENSION and LASTE, a moderately low portion of the utility space for RESCUE-JAPAN and TESLA, and the mid-portion of the utility space for ANGEL-ASPECT and SELECT 2. There is a marked pattern of downward shift of the region of benefit in the utility space as presenting core size increases. There is a dramatic difference in benefit distributions: with virtually no overlap, benefits accrue for large core patients in lowest portion of the utility space and for small core patients in the highest portion of the utility space. Conclusions: Utility Staircase displays are an efficient graphical format for conveying utility weighted–modified Rankin Scale results of large core EVT randomized trials. They accurately depict quantitative, health-related quality of life results not available from stacked bar charts and provide important insights into the distinctive treatment responses of large core patients.
Wang et al. (Thu,) studied this question.