The annual cost of managing migraine totals billions of US dollars. This retrospective economic analysis of a clinical trial comparing subcutaneous dihydroergotamine mesylate (DHE) with subcutaneous sumatriptan in the treatment of acute migraine is appropriate because, although each product has been shown to be efficacious, the acquisition cost of sumatriptan is over 3 times that of DHE. Total costs in each treatment group were calculated and applied independently to 11 clinical trial efficacy measures.
Three of the efficacy measures showed no statistically significant difference between treatment arms, leading to a decision to use the less expensive DHE. In 4 of the efficacy measures, DHE was the obvious choice because it is more efficacious and less expensive. For the final 4 efficacy measures, where sumatriptan is more efficacious and more expensive, incremental cost-efficacy ratios were calculated to determine the additional expenditure required to achieve outcomes associated with quick relief.
Depending on the efficacy variable chosen and the assumptions used in the model, the incremental cost-efficacy ratios ranged from $US4000 to $US6700 per year (1993 dollars) for each additional patient who is successfully treated with sumatriptan compared with DHE. Therefore, in a population of 100 migraineurs, an additional 13 to 22 patients would achieve these short term benefits of sumatriptan, although it would cost an additional $US88 395 annually, given the assumptions made. Because each product has unique advantages, we conclude that the more cost-efficacious product is dependent on the outcome of interest and the amount that the patient or provider is willing to pay to achieve that outcome.