Now that you have thought about patient population, intervention(s), and outcome, its time to design the ideal study you would do to answer your question. Don't make this harder than it needs to be, just come up with the ideal study you would do.
Okay...what study design protocol would you use AND what's the best study design likely to have been published.....
Randomized control trial
Prospective comparative study
Retrospective case-control study
Now, how many study arms would be in your study. Are you interested in comparing your intervention to placebo, to another intervention, or both.