Does having bad epilepsy make you a good surgical candidate? A number needed to treat analysis.

Epilepsy surgery is an established treatment for drug-resistant epilepsy, offering a realistic prospect of seizure freedom in well-selected candidates. However, surgery is sometimes offered to individuals with a low probability of seizure freedom when it is framed as potentially "life-saving" on the basis of the elevated mortality associated with uncontrolled epilepsy. We examined this rationale using absolute risk reduction and number needed to treat (NNT) analyses derived from published mortality rates (deaths per 1000 person-years) in unoperated drug-resistant epilepsy, postoperative seizure-free patients, and postoperative patients who were not seizure-free. Weighted averages were used to estimate ARR and NNT for all-cause and sudden unexpected death in epilepsy (SUDEP) mortality across varying probabilities of seizure freedom and postoperative life expectancy. Compared with unoperated patients, mortality reductions were greatest in those who became seizure-free after surgery but remained modest in patients who did not. At a 50% probability of seizure freedom, the NNT to prevent one all-cause death was 146 person-years and to prevent one SUDEP was 243 person-years; with higher seizure-freedom probabilities (80%), the NNT improved to 124 and 225 person-years, respectively; at 20%, it worsened to 178 and 264 person-years. Lifetime modeling demonstrated that NNT decreases sharply with increasing life expectancy, reaching 3.5 and 4.7 at 60 years postoperative life expectancy for all-cause and SUDEP mortality, respectively. These findings highlight the complexity of invoking a "life-saving" rationale for surgery in poor candidates. Patients with the highest mortality risk, those with frequent generalized seizures, are also those least likely to achieve postoperative seizure freedom and therefore least likely to realize a mortality benefit. Our analyses underscore the need for balanced, data-driven risk-benefit discussions when surgery is considered primarily on mortality grounds. PLAIN LANGUAGE SUMMARY: This study looked at whether epilepsy surgery saves lives for people whose seizures cannot be controlled with medication. We found that surgery lowers the risk of death-especially when it stops seizures completely-but the benefit is smaller for people who continue to have seizures afterwards. Because people with the most severe forms of epilepsy have a lower chance of becoming seizure-free following surgery, the idea that surgery will be "life-saving" for them needs to be considered carefully and discussed with clear, balanced information.