Someone will probably come along with more background as to why this doesn't work, but essentially you're trying to use it to separate a subordinate clause, without there being one.
In effect, you seem to be aiming for
a trail, that provides an understanding of the impact of the multiple components of educational programs in various settings, has not yet been published.
It's not really a subordinate clause and I don't think it's necessary to separate it out in this way.
It could be a matter of opinion, but
a man, whose hands were dirty, entered the room
could be considered subordinate; not essential to the main import of the sentence.
I'd leave it plain
a trail that provides an understanding of the impact of the multiple components of educational programs in various settings has not yet been published.