The only way to sort out cause and effect is to do a randomized trial, moving people around between neighborhoods and tracking their health over several years.

要想找出原因，唯一的方案就是进行随机实验，让人们住进不同的社区，并在几年内坚持跟踪他们的健康状况。

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The manuscript is a randomized trial, registered in the NLM database as NCT00931554.

这是一项随机试验，在NLM数据库中注册号为NCT00931554。

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The prevention of hip displacement has not been studied in a randomized trial as far as we know.

据我们所知，到目前为止还没有一个随机试验用来研究预防髋关节脱位。

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In a 28-week study of Alzheimer's patients, 250 were in a randomized trial to memantine or placebo.

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Then when a randomized trial showed that hormonal replacement therapy actually raised the early risk of heart attack, women were understandably upset.

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The latest study, a randomized trial of 80 women and men published in Plos One by Harvard researchers, shows that even when clinicians told women with irritable bowel syndrome they are getting fake pills, the fake pills still worked.

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