Table 1.

The traditional system for thrombosis risk in ET, the IPSET-t, and the revised IPSET-t.

Traditional score for thrombotic risk in ET
Low risk	Age <60 years	AND	No thrombosis
High risk	Age >60 years	OR	Thrombosis
IPSET-thrombosis score
Items	Points	Low risk	Intermediate risk	High risk
JAK2 V617F	2	<2 points	2 points	>2 points
Thrombosis	2
Age >60 years	1
CVR ≥1	1
Revised IPSET-thrombosis
Very low risk	Age <60 years	AND	No thrombosis	JAK2 WT
Low risk	Age <60 years	AND	No thrombosis	JAK2 V617F
Intermediate risk	Age >60 years	AND	No thrombosis	JAK2 wildtype
High risk	Age >60 years	OR	Thrombosis	JAK2 WT/V617F

CVR: cardiovascular risk factors; WT: wildtype.