Table 1.

Definition of risk 1, risk 2 and risk 3 categories

Variable	Risk 1 category	Risk 2 category	Risk 3 category
Age, years	<60, and	60 to 70, or	>70, or
Kidney function	Normal (MDRD ˃90), and	Moderate impairment (MDRD = 30–90), or	Sever impairment (MDRD ˂30), or
Liver function	Normal (MELD ˂8)	Moderate impairment (MELD = 8–14)	Sever impairment (MELD ˃14)

MDRD Modification of Diet in Renal Disease (surrogate for kidney function), MELD Model for End-Stage Liver Disease (surrogate for liver function)