Research in context
Evidence before this study
We did a systematic review of the English-language scientific literature in PubMed and Embase published up to Nov 6, 2014, using the search terms “antiepileptic”, “withdrawal”, “recurrence”, and “seizure-free”, and their synonyms. Overall risk of bias for separate studies was low for study participation, study attrition, prognostic factor measurement, and outcome measurement. 25 variables were identified as significant predictors of seizure recurrence in at least one peer-reviewed article. However, differences in study design, population, and methods limited the possibility to determine which were the strongest predictors, and how to combine those predictors to identify risks for the individual patient.
Added value of this study
This individual participant data meta-analysis of information from 1769 patients identified independent predictors of seizure relapse and eventual seizure freedom after antiepileptic drug withdrawal, and enabled the computation of individualised outcome risks. Our nomograms are validated across various populations and can be applied in all seizure-free patients, both children and adults, for whom antiepileptic drug withdrawal is being considered.
Implications of all the available evidence
The nomograms have the potential to improve patient consultations by providing evidence-based estimates of risk for antiepileptic drug withdrawal. Furthermore, future studies on prognostic factors for the outcome of antiepileptic drug withdrawal should correct for those identified as predictors in this paper.