Alongside the PSA, the manufacturer provided tornado diagrams displaying one-way sensitivity analyses for those variables that were varied in the probabilistic analyses. Within the 88 scenario analyses considered, there were only three scenarios in which GPB would be considered cost-effective at a threshold of $500,000 per QALY (i.e., at 10 times an indicative threshold of $50,000 per QALY). In two of these cases, Buphenyl (rather than Phenurate) was used as the NaPBA alternative and, in these cases, GPB dominated. In the remaining case, among patients with late-onset UCD who could not receive NaPBA, the relative risk of HACs was assumed to be 10.5 times the rate for those receiving dietary control (up from 8.42), and, in this case, GPB produced QALYs at a cost of $480,733 per QALY.