Health outcomes in recipients of blood transfusion - observational studies versus randomized clinical trials.
Health outcomes in recipients of blood transfusion - observational studies versus randomized clinical trials.
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输血者的健康结果——观察性研究与随机临床试验。
DOI：
10.1111/voxs.12018
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Murphy,EdwardL
中科院分区：
文献类型：
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作者：
Murphy,EdwardL
有充分的证据表明，输血实践因时间和地理而异，并且往往偏离基于证据的指南。另一方面，改变医生在安排输血方面的做法可能会取得成功。因此，挑战在于开发可靠的证据来支持合理的输血做法。观察性研究和随机临床试验都有各自的优势和局限性。观察性研究成本更低，通常规模更大，统计能力也随之提高，而且由于纳入了不受研究方案影响的常规环境中的大范围患者和医院，可能更具代表性。观察性研究的弱点包括未测量因素的混淆；适应症偏倚，即因输血患者比未接受输血的类似患者病情更严重而高估不良后果；事实上，现有的数据可能不适合研究问题。随机临床试验的优点是通过随机化过程将混杂和偏倚的影响降到最低。随机试验的局限性包括它们的费用，这使它们只能用于特定的研究问题，并可能限制统计能力；以及研究设计中的伦理问题，比如不能通过不输血来使用安慰剂。最后，纳入和排除标准通过限制纳入一组不同于一般医疗实践的患者，限制了结论的普遍性。在这篇综述中，我将试图说明观察性流行病学研究和随机临床试验在理解几种与输血相关的不良后果方面的补充贡献和局限性：死亡率；TRALI;墨西哥煎玉米卷;红细胞积存损伤。我的结论是，输血的疗效和不良后果的证据需要从观察性研究和临床试验的平衡组合中获得。
There is good evidence that blood transfusion practice varies by time and geography, and often departs from evidence‐based guidelines. On the other hand, interventions to change physician practice around the ordering of blood transfusions can be successful. The challenge is therefore to develop reliable evidence to support rational transfusion practice. Both observational studies and randomized clinical trials have strengths and limitations. Observational studies are cheaper and usually larger with concomitant improved statistical power, and may be more representative by including a wide range of patients and hospitals in the routine setting unaffected by a research protocol. Weakness of observational studies include confounding by unmeasured factors; indication bias, namely overestimation of adverse outcomes by the fact that transfused patients tend to be sicker than similar patients who did not receive transfusion; and the fact that available data may not suit the research question. Randomized clinical trials have the advantage of minimizing the effects of confounding and bias by virtue of the randomization process. Limitations of randomized trials include their expense which reserves them for specific research questions and may limit statistical power; and ethical problems in study design such as inability to utilize a placebo by withholding transfusion. Finally, inclusion and exclusion criteria can limit the generalizability of conclusions by restricting enrollment to a set of patients that differ from those seen in general medical practice. In this review, I shall attempt to illustrate the complementary contributions and limitations of observational epidemiological studies and randomized clinical trials in understanding several transfusion‐related adverse outcomes: mortality; TRALI; TACO; and the RBC storage lesion. I conclude that evidence for the efficacy and adverse outcomes of blood transfusion needs to be obtained from a balanced combination of observational studies and clinical trials.