Abstract：
OBJECTIVE: The objective of the present study was to model the effects of a reduced number of treatment centres for acute type A aortic dissection on preclinical transportation distance and time. We examined whether treatment in selected centres in Germany would be implementable with respect to time to treatment.
METHODS: For our transportation model, the number of aortic dissections and respective mean annual volume were collected from the annual quality reports (2015-2017) of all German cardiac surgery centres (n = 76). For each German postal code, the fastest and shortest routes to the nearest centre were calculated using Google Maps. Furthermore, we analysed data from the German Federal Statistical Office from January 2005 to December 2015 to identify all surgically treated patients with acute type A aortic dissection (n = 14 102) and examined the relationship between in-hospital mortality and mean annual volume of medical centres.
RESULTS: Our simulation showed a median transportation distance of 27.13 km and transportation time of 35.78 min for 76 centres. Doubling the transportation time (70 min) would allow providing appropriate care with only 12 medical centres. Therefore, a mean annual volume of >25 should be obtained. High mean annual volume was associated with significantly lower in-hospital mortality rates (P < 0.001). A significantly lower mortality rate of 14% was observed (P < 0.001) if a mean annual volume of 30 was achieved.
CONCLUSIONS: Operationalizing the volume-outcome relationship with fewer but larger medical centres results in lower mortality, which outweighs the disadvantage of longer transportation time.
METHODS: For our transportation model, the number of aortic dissections and respective mean annual volume were collected from the annual quality reports (2015-2017) of all German cardiac surgery centres (n = 76). For each German postal code, the fastest and shortest routes to the nearest centre were calculated using Google Maps. Furthermore, we analysed data from the German Federal Statistical Office from January 2005 to December 2015 to identify all surgically treated patients with acute type A aortic dissection (n = 14 102) and examined the relationship between in-hospital mortality and mean annual volume of medical centres.
RESULTS: Our simulation showed a median transportation distance of 27.13 km and transportation time of 35.78 min for 76 centres. Doubling the transportation time (70 min) would allow providing appropriate care with only 12 medical centres. Therefore, a mean annual volume of >25 should be obtained. High mean annual volume was associated with significantly lower in-hospital mortality rates (P < 0.001). A significantly lower mortality rate of 14% was observed (P < 0.001) if a mean annual volume of 30 was achieved.
CONCLUSIONS: Operationalizing the volume-outcome relationship with fewer but larger medical centres results in lower mortality, which outweighs the disadvantage of longer transportation time.
摘要：
目的：本研究的目的是模拟急性A型主动脉夹层治疗中心数量减少对临床前转运距离和时间的影响。我们检查了德国选定中心的治疗在治疗时间方面是否可实施。
方法：对于我们的运输模型，主动脉夹层的数量和各自的年平均体积来自德国所有心脏手术中心的年度质量报告(2015-2017)(n=76).对于每个德国邮政编码，使用Google地图计算了到达最近中心的最快和最短路线。此外，我们分析了德国联邦统计局1月份的数据2005年至12月2015年确定所有接受手术治疗的急性A型主动脉夹层患者（n=14102），并检查院内死亡率与医疗中心年平均容量之间的关系。
结果：我们的模拟显示，76个中心的中位运输距离为27.13km，运输时间为35.78min。将运输时间加倍（70分钟）将仅允许在12个医疗中心提供适当的护理。因此,应获得>25的平均年交易量。高的年平均容量与显著较低的住院死亡率相关(p<0.001)。如果年平均容量达到30，则观察到14％的死亡率显着降低（p<0.001）。
结论：与数量较少但规模较大的医疗中心进行容量-结局关系的操作可降低死亡率，这超过了运输时间较长的缺点。
方法：对于我们的运输模型，主动脉夹层的数量和各自的年平均体积来自德国所有心脏手术中心的年度质量报告(2015-2017)(n=76).对于每个德国邮政编码，使用Google地图计算了到达最近中心的最快和最短路线。此外，我们分析了德国联邦统计局1月份的数据2005年至12月2015年确定所有接受手术治疗的急性A型主动脉夹层患者（n=14102），并检查院内死亡率与医疗中心年平均容量之间的关系。
结果：我们的模拟显示，76个中心的中位运输距离为27.13km，运输时间为35.78min。将运输时间加倍（70分钟）将仅允许在12个医疗中心提供适当的护理。因此,应获得>25的平均年交易量。高的年平均容量与显著较低的住院死亡率相关(p<0.001)。如果年平均容量达到30，则观察到14％的死亡率显着降低（p<0.001）。
结论：与数量较少但规模较大的医疗中心进行容量-结局关系的操作可降低死亡率，这超过了运输时间较长的缺点。
