Surgery for Drug-Resistant Temporal Lobe Epilepsy Is Cost-Effective in the U.S.

From the perspective of cost-effectiveness, U.S. patients with drug-resistant temporal lobe epilepsy (DR-TLE) should be referred for evaluation for epilepsy surgery “without hesitation,” concludes a new model-based analysis from Cleveland Clinic researchers.

The study, published ahead of print by Neurology on July 8, revealed two main findings:

• TLE surgery is cost-effective relative to continued medical management in the U.S. among adult patients who are determined to be surgical candidates.
• Surgical evaluation is cost-effective in patients with DR-TLE in the U.S. even if a patient’s probability of being deemed a surgical candidate is as low as 5%.

“The clinical effectiveness of epilepsy surgery for well-selected patients with pharmacoresistant temporal lobe epilepsy has been well established, but surgery remains an underutilized treatment option, in part because it is viewed as costly,” says the study’s senior investigator, Lara Jehi, MD, MHCDS, Research Director in Cleveland Clinic’s Epilepsy Center and Chief Research Information Officer for Cleveland Clinic health system. “But we have demonstrated that, compared with continued medical management, epilepsy surgery is actually cost-saving in the long run for patients already determined to be good surgical candidates. We also found that, at a population level, even when a patient with DR-TLE is not known to qualify for epilepsy surgery, referral for a surgical evaluation to assess the patient’s surgical candidacy remains the most cost-effective management option.”

Methodology essentials

The study was performed using a Markov decision-analytic model. The primary analysis assessed whether surgery was cost-effective relative to continued medical management in adults with DR-TLE deemed to be surgical candidates. A secondary analysis assessed the cost-effectiveness of evaluation for epilepsy surgery among adults diagnosed with DR-TLE. Each analysis was done using a lifetime horizon.

Both healthcare and societal perspectives were used, with the former including direct healthcare costs (such as cost of surgery and anti-epileptic drugs) and the latter including direct costs plus indirect costs (such as lost earnings). Cost-effectiveness was evaluated by determining whether the strategy of interest (surgery or surgical evaluation) was more effective and less costly than the alternative or, if it was more effective but more costly, by using the incremental cost-effectiveness ratio (ICER) to determine effectiveness in terms of societal willingness to pay, expressed in dollars per additional quality-adjusted life-year (QALY) gained. In the U.S., healthcare interventions that cost $50,000 to $150,000/QALY are generally considered reasonable and cost-effective.

The analyses were based on data from Cleveland Clinic and from a meta-analysis of published literature involving adult patients with DR-TLE, with drug resistance defined as continued seizures despite adequate trials of at least two appropriately chosen anti-epileptic drugs. “Parameter estimates were derived from pooled estimates from multiple component studies,” the researchers note. Costs were adjusted to 2019 U.S. dollar equivalents.

Findings at a glance

The analyses revealed the following:

• Among surgery-eligible patients with DR-TLE, epilepsy surgery is cost-effective compared with continued medical management by virtue of actually being cost-saving (mean cost of $328,000 vs. $423,000, respectively, per case using a healthcare perspective) and by having only a marginally higher cost per QALY gained ($31,667). For these surgery-eligible patients, surgery was found to become cost-effective within three to four years, depending on whether a societal or healthcare perspective was used. From a societal perspective, 89% of simulations within the model favored surgery over a lifetime horizon.
• Among the overall population of patients with DR-TLE, referral for surgical evaluation was associated with a marginally higher mean cost per case compared with continued medical management, which translated to a modest cost per QALY gained ($16,667 using a healthcare perspective), considerably lower than the cost of other healthcare interventions widely accepted as reasonable and cost-effective. Referral for surgical evaluation became a cost-effective strategy across the cohort within five to seven years, depending on the perspective used. Notably, the model showed that referral for evaluation is likely to be cost-effective even if the chance that the patient eventually will be deemed a surgical candidate is as low as 5%.

Don’t let cost deter referral for surgical evaluation

While conceding that their study carries the limitations of any cost-effectiveness analysis using pooled data and multiple assumptions, the researchers note that it is a much-needed assessment of a pressing research question. The study is the first cost-effectiveness analysis of epilepsy surgery in the U.S. in more than two decades, and the applicability of analyses from other nations is highly limited by dramatic differences in these nations’ healthcare cost structures.

“In contrast to traditional reluctance to refer patients for surgical evaluation due to concern over up-front costs, our findings suggest that a referral-based strategy is actually the cost-effective approach for patients with drug-resistant temporal lobe epilepsy,” says Dr. Jehi. “The cost of surgical evaluation is absolutely reasonable, even in patients with a low likelihood of being deemed a surgical candidate. In patients who have a high chance of surgical eligibility, evaluation is likely to be cost-saving.”

A key next step for research in this area is development of cost-effectiveness prediction models that can be customized to individual patient profiles, Dr. Jehi adds. “In the meantime, our findings strengthen the growing case for more widespread consideration of surgery for patients with medically refractory temporal lobe epilepsy. The up-front cost of surgical evaluation is undeniably smaller than the price ultimately paid by patients, society and our healthcare system with an unchallenged strategy restricted to medications alone.”