Table 3.

Level of scientific evidence (Haute Autorité de Santé, High Autority of Health)

I	Large randomized controlled trials with undeniable results
II	Small randomized controlled trials and uncertain outcomes
III	Non-randomized trials with control groups contemporaries
IV	Comparative non-randomized groups with historical controls and case-control studies
V	No control groups, patient series
	Case reports
	Expert recommandation