<International Circulation>:  What are the limitations? Are those covered by Medicare a representative cohort?

　　《国际循环》：那么研究的局限性如何？那些医疗保险受益人是有代表性的队列吗？
　　Dr Dodson:  We have everybody who is insured by Medicare and everyone over 65 and everyone who received a primary prevention-type device， but what some hospitals have done (and indeed it is the majority of hospitals) is to just submit data for everyone regardless of payer and regardless of primary or secondary prevention. The secondary prevention population is sizable and ICDs used to be mainly for secondary prevention. Again， it is not 100% of ICDs in the country，but it includes a large number. With that said， there are limitations in that 20% of patients are not being captured by the registry. Over time， it is becoming increasingly comprehensive whereas initially it was mandated that only certain types of patients had data submitted. It is easier to submit data for everyone and there is no need to differentiate who is primary prevention and who is secondary prevention. That allows us to analyze primary versus secondary， for example in terms of prevention and outcomes and a range of other things. The figures are roughly that 78% of hospitals submit data for all ICDs whether primary or secondary， Medicare or non-Medicare， and that constitutes 85% of the total ICD population. I think that larger hospitals submit data for all patients more than smaller hospitals， so there are still patients that are being missed， but the take-home message right now is that there is no other tool that allows us to look at outcomes on such a large scale.

　　Dr Dodson: 我们的研究中包括了有医疗保险的患者、65岁以上的患者和接受了一级预防装置植入的患者，但一些医院所做的（实际上大多数医院如此）仅仅是提交数据而不论谁支付费用，也不论是一级还是二级预防。二级预防人群相当巨大，ICDs曾经被主要用于二级预防。再次强调，研究没有覆盖这个国家100%的ICDs治疗患者，但的确包括了相当多的患者。就此而言，20%的患者未被纳入是本注册研究局限性之一。随着时间推移，注册数据变得越来越全面，而最初时仅要求特定类型的患者提交数据。实际上患者提交数据非常便利，没有必要区分哪些患者是一级预防、哪些患者是二级预防。这使得我们能够分析对比一级和二级预防的结局及其他问题。大约78%的医院提交了所有ICDs数据，不论一级还是二级预防、不论有无医疗保险，这些数据代表了ICD总人群的85%。我想较大的医院提供了比较小医院更多的全体患者数据，因此仍有部分患者的数据缺失。关键是，就目前而言，没有其他工具能够使我们观察如此大量患者的结局。