The IPSET thrombosis model derives form multivariate analysis of 831 patients diagnosed with essential thrombocythemia by WHO criteria within the preceding year, at one of seven centers. Most high-risk patients received cytoreductive therapy with hydroxyurea, anagrelide and busulfan, while most low-risk patients did not. Most patients received low-dose Aspirin. The model was validated in an external cohort of 329 patients.
|Risk variables||Hazard ratio||Score Points|
|Age > 60 years||1.5||1|
|Cardiovascular risk factors||1.56||1|
|Score||Risk category||Annual thrombosis risk|
|≥ 3||High risk||3.56%|
Barbui T, Finazzi G, Carobbio A, Thiele J, Passamonti F, Rumi E et al. Development and validation of an International Prognostic Score of thrombosis in World Health Organization-essential thrombocythemia (IPSET-thrombosis). Blood 2012; 12: 5128-33.