The cost effectiveness of surgery for drug resistant temporal lobe epilepsy in the US

Objective: Surgery is an effective but costly treatment for many patients with drug resistant temporal lobe epilepsy (DR-TLE). We aim to evaluate whether, in the United States, 1) surgery is cost-effective compared to medical management for patients deemed surgical candidates, 2) surgical evaluation is cost-effective for DR-TLE patients in general.

Methods: We use a semi-Markov model to assess the cost-effectiveness of surgery and surgical evaluation over a lifetime horizon. We use 2nd order Monte Carlo simulations to conduct probabilistic sensitivity analyses to estimate variation in model output. We adopt both healthcare and societal perspectives, including direct healthcare costs (e.g. surgery, AEDs) and indirect costs (e.g. lost earnings by patients and care providers.) We compare incremental cost-effectiveness ratio (ICER) to societal willingness-to-pay (~$100,000 per Quality Adjusted Life Year) to determine whether surgery is cost-effective.

Results: Epilepsy surgery is cost effective compared to medical management in surgically eligible patients by virtue of being cost saving ($328K vs. 423K) and more effective (16.6 QALY vs. 13.6 QALY) than medical management in the long run. Surgical evaluation is cost-effective in DR-TLE patients even if the probability of being deemed a surgical candidate is only 5%. From a societal perspective, surgery becomes cost effective within 3 years and 89% of simulations favor surgery over the lifetime horizon.

Conclusion: For surgically eligible DR-TLE patients, surgery is cost-effective. For DR-TLE patients in general, referral for surgical evaluation (and possible subsequent surgery) is cost-effective. DR-TLE patients should be referred for surgical evaluation without hesitation on cost-effectiveness grounds.

研究目标：手术是治疗众多耐药性颞叶癫痫（drug resistant temporal lobe epilepsy, DR-TLE）患者的有效手段，但治疗成本高昂。本研究旨在评估美国场景下，① 对于符合手术指征的患者，手术相较于药物治疗是否具备成本效果；② 整体而言，针对耐药性颞叶癫痫患者开展手术评估是否具备成本效果。

研究方法：本研究采用半马尔可夫模型（semi-Markov model），以终身时长为研究视角，评估手术及手术评估的成本效果。我们采用二阶蒙特卡洛模拟开展概率敏感性分析，以估算模型输出结果的变异程度。本研究同时采用医疗体系与社会双视角，纳入直接医疗成本（如手术费用、抗癫痫药物（Antiepileptic Drugs, AEDs）支出）与间接成本（如患者及照护者的误工损失）。我们将增量成本效果比（incremental cost-effectiveness ratio, ICER）与社会支付意愿（约每质量调整生命年（Quality Adjusted Life Year, QALY）10万美元）进行对比，以此判定手术是否具备成本效果。

研究结果：从长期维度来看，符合手术指征的耐药性颞叶癫痫患者采用手术治疗，相较于药物治疗具有成本效果优势：不仅可节约医疗成本（手术组32.8万美元 vs 药物组42.3万美元），同时可获得更高的QALY（16.6 vs 13.6）。即便仅5%的耐药性颞叶癫痫患者可被判定为符合手术指征，整体开展手术评估仍具备成本效果。从社会视角来看，手术可在3年内实现成本效果正向转化，且89%的模拟结果显示，在终身研究时长内手术方案更具优势。

研究结论：对于符合手术指征的耐药性颞叶癫痫患者，手术治疗具备成本效果。整体而言，针对耐药性颞叶癫痫患者转诊开展手术评估（及后续可能实施的手术治疗）均具备成本效果。基于成本效果的考量，耐药性颞叶癫痫患者应毫无迟疑地转诊接受手术评估。