Help with PICO question please

[lovelylady42]

This is the topic for my PICO question:

Advantages/Disadvantages of negative pressure wound therapy (or other types of therapy) or various treatments on wound healing

This is what I have so far:

In patients with pressure ulcers (p) what is the effect of pressure wound therapy (I) as compared with_______ © on wound healing (o)

What would I put for the C? Do I just choose a random type of wound healing therapy to compare it to? I think I have to be more specific than just "various treatments"

[Double-Helix, BSN, RN]

I'd choose the most common type of dressing. When a patient is not on a wound vac, the most common dressing you will see ordered is a wet-to-dry gauze dressing.