A randomized controlled trial of (yoga training) may result in calm.
A randomized controlled trial can be constituted-of-or-filled-with (yoga training).
A meta-analysis of randomized controlled trials may conclude that something-is-the-case.
Randomized controlled trials can be constituted-of-or-filled-with patients.
Meta-analyses can be constituted-of-or-filled-with randomized controlled trials.