Interventional Neuroradiology Research Unit, Department of Radiology, International Consortium of Neuroendovascular Centres, University of Montreal, Centre Hospitalier de l'Université de Montreal, Notre-Dame Hospital, Quebec, Canada.
AJNR Am J Neuroradiol. 2011 May;32(5):809-12. doi: 10.3174/ajnr.A2516. Epub 2011 Apr 14.
Two recent publications from Helsinki and Toronto that investigated the natural history of brain AVMs are the background topic for reviewing some principles and pitfalls of prognostic studies. Multivariable prognostic research involves 3 steps: developing the prognostic model, validating its performance in other individuals, and assessing its clinical impact on patients' outcomes. Unfortunately, the predictive ability of the model can be poor when it is applied to a new population, and clinical impact studies are rarely performed. Models that have not been validated should not be used to inform clinical decisions. Unfortunately, for rare outcomes in rare diseases, clinical data are limited. Although the 2 studies on brain AVMs may represent the best data currently available, they still included few patients with events and there are several methodologic concerns undermining the reliability of results. The estimates of risk of rupture per year are uncertain. Multiplying those uncertain numbers by the life expectancy of individuals can inflate error beyond control. Hence relying on these estimates to make clinical decisions may be dangerous.
两篇最近发表于赫尔辛基和多伦多的研究大脑动静脉畸形自然史的文献为综述预后研究的一些原则和陷阱提供了背景资料。多变量预后研究包括 3 个步骤：建立预后模型，在其他个体中验证其性能，以及评估其对患者结局的临床影响。不幸的是，当将模型应用于新人群时，其预测能力可能很差，并且很少进行临床影响研究。未经验证的模型不应用于为临床决策提供信息。不幸的是，对于罕见疾病中的罕见结局，临床数据有限。尽管这两项关于脑动静脉畸形的研究可能代表了目前可获得的最佳数据，但它们纳入的发生事件的患者仍然较少，并且存在几个方法学问题，削弱了结果的可靠性。每年破裂的风险估计值不确定。将这些不确定的数字乘以个体的预期寿命可能会导致误差失控。因此，依赖这些估计值来做出临床决策可能是危险的。
