科恩博士说：“NHANESIII是一项观察上的研究而不是一次临床试验，所以，关于因果没有一个确定的结论是可能的。”
Since NHANES III was an observational study and not a clinical trial, no definite conclusions about cause and effect were possible, says Dr. Cohen.
认为酒精有益的许多研究结果都是从长期观察的测试者身上得来，并不是随机临床试验的方式，相比起来后者更为可信。
Much of the research on alcohol's benefit comes from studies that observe people over time rather than from controlled clinical trials, which are more reliable.
报告真实资料的个案报告、病例分析、调查和其他观察性研究均包括在内，然而评论文章、译文和临床试验均未包括在内。
Case reports, case series, surveys and other observational studies were included if they reported factual data, but review articles, translations and clinical trials were excluded.
导致观察性研究和大规模随机临床试验结果之间不一致的可能原因有多种。
There are multiple possible reasons for discrepant results between observational studies and large randomized trials.
研究者警示，这种观察研究与临床试验未必有同样的科学意义。
Researchers cautioned that this was an observational study that does not necessarily carry the same scientific weight as a blinded clinical trial.
研究者对癌症临床试验观察发现在这些试验中只有25%的人年龄超过65岁。
The research looked at cancer clinical trials and found that only 25 percent of patients in such trials were over the age of 65.
我们有十多年的医学和临床研究经验，包括II- IV期临床试验和非干预观察性研究。
We have more than 10 years of experience in medical research worldwide which include phase II - phase IV clinical trials and non-interventional observational studies.
我们有十多年的医学和临床研究经验，包括II- IV期临床试验和非干预观察性研究。
We have more than 10 years of experience in medical research worldwide which include phase II - phase IV clinical trials and non-interventional observational studies.
应用推荐