BACKGROUND In this study, we aimed to understand the trends in total and itemized medical expenses, especially of disease-modifying therapy (DMT), for multiple sclerosis (MS) in Japan through an analysis of health insurance claims data. METHODS We analyzed a database containing health insurance claims data from hospitals that have adopted the Diagnosis Procedure Combination/Per-Diem Payment System in Japan. According to an algorithm based on diagnosis codes, data for all patients diagnosed with MS from April 2008 to July 2016 were extracted. Medical costs, rate of each medical treatment, and rate of relapses were analyzed by calendar-year. Medical costs in the month of relapse were compared with average medical costs per month of all MS patients by a cross-sectional analysis. RESULTS Four thousand three hundred seventy-four MS patients were identified in the database. Total medical cost per patient per month (PPPM) increased from ¥87,640 (US$787.7 or €723.0 as of May 2017) to ¥102,846 (US$924.4 or €848.4) during the study period. This increment was mainly attributed to the growth in cost of outpatient DMT prescriptions, which increased from ¥23,039 (US$207.1 or €190.1) to ¥51,351 (US$461.5 or €423.6). In contrast, the rate of hospitalizations and relapses PPPM decreased during the study period (from 0.053 to 0.030, and 0.032 to 0.019, respectively). Medical costs in the month of relapse (¥424,661, US$3816.8 or €3503.1) were 3.57 times higher than the average monthly costs for all MS patients (¥119,021, US$1069.8 or €981.8), with the majority comprising hospitalization cost. CONCLUSION Concomitant with the increased usage of DMT, the total medical cost for treating MS is increasing in Japan. However, rates of relapse and hospitalization have shown a decreasing trend. Although this study does not show the direct causality between DMT and reduction of relapse rates/fewer hospitalizations among MS patients, a reduction in hospital costs has been revealed concomitantly with the increasing prevalence of DMT.

中文翻译：

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基于对健康保险理赔数据库的分析，日本最近的医疗费用和多发性硬化症复发率的转变。

背景技术在本研究中，我们旨在通过分析健康保险理赔数据来了解日本多发性硬化症（MS）的总和逐项医疗费用的趋势，尤其是疾病改善疗法（DMT）的趋势。方法我们分析了一个数据库，其中包含来自日本采用“诊断程序组合/按日付款”支付系统的医院的健康保险理赔数据。根据基于诊断代码的算法，提取了2008年4月至2016年7月所有诊断为MS的患者的数据。按日历年分析医疗费用，每次治疗的比率和复发率。通过横断面分析，将复发月份的医疗费用与所有MS患者每月的平均医疗费用进行了比较。结果在数据库中鉴定出了304例MS患者。在研究期间，每个患者每月的总医疗费用（PPPM）从87,640日元（2017年5月为787.7美元或723.0欧元）增至102,846日元（924.4美元或848.4欧元）。这种增加主要归因于门诊DMT处方费用的增长，从23,039日元（207.1美元或190.1欧元）增加到51,351日元（461.5欧元或423.6欧元）。相比之下，在研究期间，PPPM的住院率和复发率有所降低（分别从0.053降至0.030和0.032降至0.019）。复发月份的医疗费用（424,661日元，3816.8美元或3503.1欧元）是所有MS患者平均每月费用（119,021日元，1069.8美元或981.8欧元）的3.57倍，其中大部分为住院费用。结论随着DMT使用量的增加，日本治疗MS的总医疗费用也在增加。但是，复发率和住院率却呈下降趋势。尽管该研究并未显示DMT与MS患者复发率降低/减少住院之间的直接因果关系，但随着DMT患病率的增加，医院费用的减少也被揭示出来。