Outcomes
ADVERSE EVENTS
The primary outcome was the change in mean weekly attack frequency 2 years after completion of the ICON study (i.e. 3 years after ONS implantation) compared to baseline (i.e. the three months before ONS implantation). Secondary outcomes were (i) Change in mean attack frequency from baseline after 1, 2 and 5 years (ii) whether non-responders (i.e. <50% or <30% reduction in attack frequency from baseline); at the end of the ICON study became responders during long-term follow up; (iii) occurrence of adverse events; (iv) mean SF-36 scores; (v) predictive capacity of sex, age, restlessness, mean weekly attack frequency at baseline, number of autonomic symptoms and ≥50% response in week 1–4 after implantation for efficacy at two years and (vi) subjective improvement and willingness to recommend this treatment to other patients.