Predicting Response to Treatment of Epileptic Seizures: How Much Time and How Many AEDs Do We Need to Try?

Identification of Patients Who Will Not Achieve Seizure Remission Within 5 Years on AEDs Hughes DM, Bonnett LJ, Czanner G, Komárek A, Marson AG, García Fiñana M. Neurology. 2018;91(22):e2035-e2044. doi: 10.1212/WNL.0000000000006564. Epub 2018 Nov 2. PMID: 30389894. Objective: To identify people with epilepsy who will not achieve a 12-month seizure remission within 5 years of starting treatment. Methods: The Standard and New Antiepileptic Drug (SANAD) study is the largest prospective study in patients with epilepsy to date. We applied a recently developed multivariable approach to the SANAD data set that takes into account not only baseline covariates describing a patient’s history before diagnosis but also follow-up data as predictor variables. Results: Changes in number of seizures and treatment history were the most informative time-dependent predictors and were associated with history of neurologic insult, epilepsy type, age at start of treatment, sex, and having a first-degree relative with epilepsy. Our model classified 95% of patients. Of those classified, 95% of patients observed not to achieve remission at 5 years were correctly classified (95% confidence interval [CI]: 89.5%-100%), with 51% identified by 3 years and 90% within 4 years of follow-up. Ninety-seven percent (95% CI: 93.3%-98.8%) of patients observed to achieve a remission within 5 years were correctly classified. Of those predicted not to achieve remission, 76% (95% CI: 58.5%-88.2%) truly did not achieve remission (positive predictive value). The predictive model achieved similar accuracy levels via external validation in 2 independent United Kingdom-based data sets. Conclusion: Our approach generates up-to-date predictions of the patient’s risk of not achieving seizure remission whenever new clinical information becomes available that could influence patient counseling and management decisions.