How to prove without randomised controlled trials that automated external defibrillators used by the public save lives?
How to prove without randomised controlled trials that automated external defibrillators used by the public save lives?
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如何在没有随机对照试验的情况下证明公众使用的自动体外除颤器可以拯救生命？
DOI：
10.1136/heartjnl-2018-313071
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发表时间：
2018
期刊：
影响因子：
5.7
通讯作者：
N. Mpotos
中科院分区：
文献类型：
--
作者：
P. Calle;N. Mpotos
在他们的《心脏杂志》手稿中，Aschieri等人报告了自动体外除颤器(AED)的可用性对业余体育中心心脏骤停(SCA)后存活率的令人印象深刻的影响。1在这项观察性研究中，作者分析了来自意大利皮亚琴察地区所有出院SCA病例的登记数据。使用预先确定的变量‘位置’，他们选择了26个病例。由于AED是在18年期间逐步引入的，因此可以根据AED的现场存在情况进行比较。在有和没有现场AED的体育中心，神经完整存活率分别为93%(14/15)和9%(1/11)。
乍一看，这种令人印象深刻的差异应该会导致明显明确的结论。然而，仔细观察方法和数据，就会敦促人们谨慎行事，因为至少应该提到四个可能导致偏见的问题(往往是相互关联的)。首先，由于体育中心决定是否启动当地的AED项目，因此AEDs不是随机分配的，这意味着所有结果都容易出现偏差。其次，没有登记崩溃的时间。虽然提交人称目击了所有病例，而且从未向紧急医疗服务(EMS)调度中心发出逮捕前症状的警报，但不能排除在有现场AED的体育中心，坍塌到呼叫间隔较短，例如，因为旨在最佳使用AED的地方运动也强调了提前致电调度中心的重要性。第三，AEDs的逐步引入(即2007年只有36个设备，而2016年为207个)反映在配备AED的站点中SCA病例的比例不断上升(即，1999年至2007年期间，每8例病例中只有1例，而2008年至…期间，每18例病例中有14例
In their Heart manuscript, Aschieri et al report an impressive impact of the availability of automated external defibrillators (AEDs) on survival after sudden cardiac arrest (SCA) in amateur sports centres.1 For this observational study, the authors analysed data from a registry on all out-of-hospital SCA cases from the Piacenza area (Italy). Using the predetermined variable ‘location’, they selected 26 cases. As AEDs were gradually introduced over an 18-year period, a comparison could be made according to the on-site presence of an AED. Neurologically intact survival rates in sports centres with and without on-site AED were 93% (14/15) and 9% (1/11), respectively.
At first glance, this impressive difference should lead to patently clear conclusions. A closer look at the methodology and the data, however, urges caution as at least four (often interrelated) issues potentially leading to bias should be mentioned. First, the AEDs were not allocated at random since the sports centres decided whether or not to start a local AED project, implying that all results are prone to bias. Second, the time of collapse was not registered. Although the authors state that all cases were witnessed and that the emergency medical services (EMS) dispatch centre was never alerted for pre-arrest symptoms, one cannot exclude that in sports centres with an on-site AED the collapse to call interval was shorter, for example, because a local campaign aiming at an optimal AED use also emphasised the importance of an early call to the dispatch centre. Third, the gradual introduction of AEDs (ie, only 36 devices in 2007 vs 207 in 2016) is reflected by an increasing proportion of SCA cases in AED-equipped sites (ie, only 1 out of 8 cases between 1999 and 2007 vs 14 out of 18 between 2008 and …