I believe that in most cases, they can be considered the same thing. It is not so important what you call them, but it is important that you understand their role in the text. If the passage contains an argument, then the premises will be offered as evidence in support of the conclusion. If the passage is simply a series of facts, then each of these facts could be considered a premise. A premise is a more broad term that refers to statements in the passage, but if it helps you to refer to them as "evidence" or "support," then you should do so. Just make sure you understand the structure of each argument.