Chen Z, et al. - This longitudinal cohort study was performed to evaluate long-term treatment outcome in patients with newly diagnosed and treated epilepsy. Overall outcomes in newly diagnosed epilepsy had not improved, despite the availability of many new antiepileptic drugs (AEDs) with differing mechanisms of action. Most patients who attain control did so with the first or second AED. The likelihood of achieving seizure freedom declined substantially with each subsequent AED regimen tried. More than 1/3^rd of patients experienced epilepsy that remained uncontrolled.

Methods

• The researchers conducted this longitudinal observational cohort study at the Epilepsy Unit of the Western Infirmary in Glasgow, Scotland.
• They included 1,795 individuals who were newly treated for epilepsy with AEDs between July 1, 1982, and October 31, 2012, in this analysis.
• For this study, all patients were followed up for a minimum of 2 years (until October 31, 2014) or until death, whichever came sooner.
• Between March 2015 and May 2016, data analysis was completed.
• Treatment with antiepileptic drugs for patients newly diagnosed with epilepsy was included as exposures.
• They assessed seizure control at the end of the study period.
• For each AED regimen prescribed, probability of achieving 1-year seizure freedom was estimated.
• After adjustments were made for demographic and clinical characteristics, multivariable models assessed the associations between risk factors and AED treatment outcome.

Results

• Among the 1,795 included patients, 964 (53.7%) were male; the median age was 33 years (range, 9-93 years).
• A total of 1,144 patients (63.7%) had been seizure free for the previous year or longer at the end of the study period.
• In this study, 993 (86.8%) were taking monotherapy among those achieving 1-year seizure freedom, and 1,028 (89.9%) had achieved seizure control with the first or second AED regimens.
• Out of the total patient pool, 906 (50.5%) remained seizure free for 1 year or longer with the initial AED.
• The second and third regimens provided an additional 11.6% and 4.4% likelihoods of seizure freedom, respectively, if this AED failed.
• Only 2.12% of patients attained optimal seizure control with subsequent AEDs.
• As per findings, epilepsy that was not successfully controlled with the first AED had 1.73 times greater odds of not responding to treatment for each subsequent medication regimen (odds ratio, 1.73; 95% CI, 1.56-1.91; P < .001).