Table 1.

Inclusion criteria of systematic reviews (PICO)

Population	Diabetic patients >18 years with foot ulcer
Intervention	Negative pressure wound therapy
Comparator	Any conventional wound dressing for diabetic ulcers
Outcome	Primary outcome: complete wound healing (healing time, change in ulcer size, granulation tissue formation) Secondary outcome: adverse events (e.g. infection, pain), and cost-effectiveness