In statistical analysis, both conventional techniques (e.g. non-parametric paired-samples and non-paired samples t-test), and more sophisticated methods will be used. The latter include i) life-table methods like Kaplan-Meier and Cox proportional hazards regression, as well as ii) generalized linear models (GEE and panel Poisson) and as a new technique in cluster headache RCTs, a competing risks regression to model the natural outcomes of the headache during the intervention. This study (n=60; the most modest scenario) is adequately powered (Type II error 0.80, type I error 0.05) to detect a true difference in attack frequency between 15 attacks/week in the placebo and 13.1 attacks/week in the Acetium arm. Given that the study subjects are enrolled among patients with typically 1-3 attacks/day, i.e., 7-21 (up to 35) attacks per week, and assuming a 10% reduction by placebo, there figures seem reasonable estimates for these power calculations.