Supplementary Material for: Cost-effectiveness analysis of endoscopic treatment versus medication strategy for proton pump inhibitor-refractory gastroesophageal reflux disease

Introduction: Potassium-competitive acid blockers are effective against proton pump inhibitor-refractory gastroesophageal reflux disease; however, their long-term use is associated with economic disadvantages. Endoscopic procedures may reduce potassium-competitive acid blocker use. This study aimed to determine the optimal treatment strategy for patients with proton pump inhibitor-refractory gastroesophageal reflux disease from a cost-effectiveness perspective.
Methods: Using a Markov state transition model to simulate symptom changes in patients with proton pump inhibitor-refractory gastroesophageal reflux disease, the cost-effectiveness of two strategies was compared: endoscopic treatment (anti-reflux mucosectomy or endoscopic submucosal dissection for gastroesophageal reflux disease) followed by potassium-competitive acid blocker versus medication with high-dose potassium-competitive acid blocker. In both strategies, potassium-competitive acid blocker maintained symptoms at the lowest controllable dose. The time horizon varied from 10 to 50 years. The quality-adjusted life year and incremental cost-effectiveness ratio were calculated. Willingness-to-pay was set at 5,000,000 Japanese yen.
Results: The quality-adjusted life years gained were 0.90 and 0.95 for the endoscopic treatment and medication strategies, respectively. The incremental cost-effectiveness ratio varied with the follow-up period after the initial treatment, with the endoscopic treatment strategy being more cost-effective than the medication strategy at ≥50 years of follow-up. A dose reduction success rate of <84.1% for high-dose potassium-competitive acid blocker and an endoscopic treatment success rate of >66.8% were required to determine the superiority of the endoscopic treatment strategy at the 50-year follow-up after treatment.
Discussion/Conclusions: The endoscopic treatment strategy is not cost-effective unless the patient is followed up for >50 years after the initial treatment.

引言：钾竞争性酸阻滞剂（Potassium-competitive acid blockers）对质子泵抑制剂难治性胃食管反流病（proton pump inhibitor-refractory gastroesophageal reflux disease）具有良好疗效，但长期使用存在经济劣势。内镜操作可减少钾竞争性酸阻滞剂的使用量。本研究旨在从成本效果视角，明确质子泵抑制剂难治性胃食管反流病患者的最优治疗策略。
方法：本研究采用马尔可夫状态转换模型（Markov state transition model）模拟质子泵抑制剂难治性胃食管反流病患者的症状变化，对比两种治疗策略的成本效果：其一为内镜治疗（针对胃食管反流病的抗反流黏膜切除术或内镜黏膜下剥离术（endoscopic submucosal dissection））后序贯钾竞争性酸阻滞剂治疗，其二为大剂量钾竞争性酸阻滞剂药物治疗。两种策略中，钾竞争性酸阻滞剂均以可控制的最低剂量维持症状。研究时限设置为10至50年，计算质量调整生命年（quality-adjusted life year）与增量成本效果比（incremental cost-effectiveness ratio），并将支付意愿（Willingness-to-pay）设定为500万日元。
结果：内镜治疗组与药物治疗组获得的质量调整生命年分别为0.90与0.95。增量成本效果比随初始治疗后的随访周期发生变化，当随访周期≥50年时，内镜治疗策略的成本效果优于药物治疗策略。若要在治疗后50年随访时证实内镜治疗策略的优越性，则需满足大剂量钾竞争性酸阻滞剂的剂量降低成功率＜84.1%，且内镜治疗成功率＞66.8%。
讨论与结论：除非患者在初始治疗后接受超过50年的随访，否则内镜治疗策略不具备成本效果优势。