Patients and questionnaires
MOS, COMPLICATIONS
For logistic reasons, only Dutch patients who had completed the full 48-week ICON study were invited for prospective structured follow-up every 6 months for at least two years but if possible longer.ICON study participants were asked to participate and enrolled in the L-ICON follow-up study immediately after completion of the ICON study, 48 weeks after ONS implantation. Meanwhile, the ICON study continued to enrol new patients until 3 December 2017. Therefore, initial ICON participants could start earlier in L-ICON and be followed longer than ICON participants enrolled later in the ICON study. Inclusion for the L-ICON study was stopped after the last ICON participant was enrolled in L-ICON and followed for ≥2 years (i.e. ≥3 years after ONS implantation).Participants who consented had to complete two web-based questionnaires every six months. Unless they had explicitly withdrawn, the participants were reminded to complete the questionnaires six and two weeks before and two and six weeks after every six-month deadline. The six-monthly reminders were sent regardless of whether or not they had submitted the questionnaires six months earlier.One questionnaire included questions on: (i) neurostimulator use; (ii) side effects and complications; (iii) mean weekly attack frequency over the past six months; (iv) whether participants experienced improvement and if so, an estimated percentage of improvement; and (v) whether patients would recommend this treatment to a similar patient on a five-point scale. The other questionnaire consisted of the MOS 