董宋萍的回答：
The ICMJE defines a clinical trial as any research project that prospectively assigns people to an intervention, with or without concurrent comparison or control groups, to study the cause-and-effect relationship between a health-related intervention and a health outcome. 这里对临床试验的要求都是干预性（interventional）的。 也有非干预性的规定，这里没贴下，fa你私信了。
岁月的童话的回答：