Table 3.

GRADE system for quality of evidence

Author	High	Moderate	Low	Very low
Basnet et al.(17)	X
Thill et al.(18)	X
Needleman et al.(19)		X
Williams, et al.(20)			X
Beers et al.(21)			X
Mayordomo-Colunga et al.(17)			X
Carroll et al.(4)				X
Akingbola et al.(22)				X
Haggenmacher et al.(23)				X