Long-term clinical outcomes and economic evaluation of the ketogenic diet versus care as usual in children and adolescents with intractable epilepsy

•The KD group resulted in more responders and showed greater improvement on seizure severity.•The KD did not lead to a worsening of side-effects other than gastro-intestinal problems (at 4 months follow-up only).•The costs of the total follow-up were higher in the KD group compared to the control group.•As only a minimal difference was found between the KD and the CAU group regarding QALYs, inconclusive cost per QALY ratios resulted.•Compliance with the KD was shown to be difficult in some patients, resulting in a retention rate of 58% which is in line with previous literature.

ObjectiveTo examine long-term retention rate, clinical outcomes, cost-utility and cost-effectiveness of the Ketogenic Diet (KD) compared with care as usual (CAU) in children and adolescents with intractable epilepsy from a societal perspective.MethodsParticipants were randomized into a KD or CAU group. Seizure frequency, quality adjusted life years (QALYs), side-effects, seizure severity, health care costs, production losses, patient and family costs were assessed at baseline and during 16-months of follow-up. Incremental cost-effectiveness ratios (ICERs) (i.e. cost per QALY and cost per responder) and cost-effectiveness acceptability curves are presented.Results48 children were included in the analyses of this study (26 from KD group). In total, 58% of the KD group completed the follow-up of 16 months; 11 dropped-out for various reasons. At 16 months, 35% of the KD participants had a seizure reduction ≥ 50% from baseline, compared with 18% of the CAU participants. Mean costs per patient in the CAU group were €53,367 (extrapolated) compared to €61,019 per patient in the KD group, resulting in an ICER of €46,564 per responder. Cost per QALY rose well above any acceptable ceiling ratio. At 4-months' follow-up, the KD group showed significantly more gastro-intestinal problems compared to the CAU group. At 16 months, the KD group reported fewer problems compared to CAU. Furthermore, 46.2% of the KD group reported a decrease in severity of their worst seizure compared to 32% of the CAU group.ConclusionThe KD group resulted in more responders and showed greater improvement on seizure severity. Furthermore, the KD did not lead to worsening of side-effects other than gastro-intestinal problems (only at 4 months' follow-up). However, as only a minimal difference in QALYs was found between the KD group and the CAU group, the resulting cost per QALY ratios were inconclusive.