更改

There are two processes involved in randomizing patients to different interventions. First is choosing a randomization procedure to generate an unpredictable sequence of allocations; this may be a simple random assignment of patients to any of the groups at equal probabilities, may be "restricted", or may be "adaptive." A second and more practical issue is allocation concealment, which refers to the stringent precautions taken to ensure that the group assignment of patients are not revealed prior to definitively allocating them to their respective groups. Non-random "systematic" methods of group assignment, such as alternating subjects between one group and the other, can cause "limitless contamination possibilities" and can cause a breach of allocation concealment.

There are two processes involved in randomizing patients to different interventions. First is choosing a randomization procedure to generate an unpredictable sequence of allocations; this may be a simple random assignment of patients to any of the groups at equal probabilities, may be "restricted", or may be "adaptive." A second and more practical issue is allocation concealment, which refers to the stringent precautions taken to ensure that the group assignment of patients are not revealed prior to definitively allocating them to their respective groups. Non-random "systematic" methods of group assignment, such as alternating subjects between one group and the other, can cause "limitless contamination possibilities" and can cause a breach of allocation concealment.

有两个过程涉及到随机化的病人不同的干预措施。首先是选择一个随机化程序来生成一个不可预测的分配序列; 这可能是一个简单的随机分配病人到任何一个组在相同的概率，可能是“受限制的”，或者可能是“适应性的”第二个更实际的问题是分配隐瞒，即采取严格的预防措施，以确保在明确分配病人到各自的群体之前，不会透露病人的群体分配。非随机的“系统的”分配方法，例如在一组和另一组之间交换主题，可以造成“无限的污染可能性”，并可能造成分配隐藏的破坏。

有两个过程涉及到随机化的病人接受到不同的干预。首先是选择一个随机化程序来生成一个不可预测的分配方式; 这可能是一个将病人简单的随机等概率分配到任何一个组，这一过程可能是“受限制的”，或者可能是“适应性的”。第二个更实际的问题是分配隐瞒，即采取严格的预防措施，以确保在将病人到各自的群体之前，不会透露病人的群体分配。非随机的“系统的”分配方法，例如在一组和另一组之间交换主题，可以造成“无限的污染概率”，并可能造成分配隐藏的破坏。

The RCT method variations may also create cultural effects that have not been well understood.<ref name="Jain-2010">{{Cite journal | author = Jain SL | title = The mortality effect: counting the dead in the cancer trial | journal = [[Public Culture]] | volume = 21 | issue = 1 | pages = 89–117 | year = 2010 | doi = 10.1215/08992363-2009-017 | s2cid = 143641293 | url = https://pdfs.semanticscholar.org/aea1/45d2ff3b9c36b283cd9ca8cb61b839ef6993.pdf | archive-url = https://web.archive.org/web/20200220002207/https://pdfs.semanticscholar.org/aea1/45d2ff3b9c36b283cd9ca8cb61b839ef6993.pdf | url-status = dead | archive-date = 2020-02-20 }}</ref> For example, patients with terminal illness may join trials in the hope of being cured, even when treatments are unlikely to be successful.

The RCT method variations may also create cultural effects that have not been well understood.<ref name="Jain-2010">{{Cite journal | author = Jain SL | title = The mortality effect: counting the dead in the cancer trial | journal = [[Public Culture]] | volume = 21 | issue = 1 | pages = 89–117 | year = 2010 | doi = 10.1215/08992363-2009-017 | s2cid = 143641293 | url = https://pdfs.semanticscholar.org/aea1/45d2ff3b9c36b283cd9ca8cb61b839ef6993.pdf | archive-url = https://web.archive.org/web/20200220002207/https://pdfs.semanticscholar.org/aea1/45d2ff3b9c36b283cd9ca8cb61b839ef6993.pdf | url-status = dead | archive-date = 2020-02-20 }}</ref> For example, patients with terminal illness may join trials in the hope of being cured, even when treatments are unlikely to be successful.