In evaluating the risk of thrombosis for patients with essential thrombocythemia, we consider three important clinical factors. These factors are:

- Age greater than 60 years
- Presence of the JAK2V617F mutation
- History of thrombosis

Each of these factors contributes to determining the level of thrombosis risk, which is categorized into four possible outcomes.

The system assesses these inputs as follows:

- If the patient is over 60 and has the JAK2V617F mutation, or if they have a history of thrombosis, the risk is identified as high. This reflects the compounded risk factors that significantly elevate the potential for thrombosis.
- If the only input is age greater than 60 without the other two factors, the risk is considered intermediate. Age alone is a noteworthy risk factor, though not as severe without additional considerations.
- In cases where the patient has only the JAK2V617F mutation, the risk is classified as low. The mutation is associated with thrombosis risk, but the absence of age or previous thrombosis incidents moderates this classification.
- For patients who do not present any of these risk factors, the associated risk level is evaluated as very low. This suggests a relatively minor probability of developing thrombosis under current clinical understanding.

Through this structured evaluation, healthcare providers are equipped with a straightforward method to assess thrombosis risk, guiding further diagnostic or therapeutic decisions tailored to each patient's risk profile.

The Revised International Prognostic Score for Essential Thrombocythemia (IPSET-thrombosis) is a clinical calculator used in the management of patients with essential thrombocythemia (ET). Essential thrombocythemia is a rare chronic blood disorder characterized by the overproduction of platelets by megakaryocytes in the bone marrow. 

The Revised IPSET score is used to stratify patients into risk categories (low, intermediate, and high) based on their likelihood of developing thrombotic complications. This score takes into account factors such as age, prior thrombosis, cardiovascular risk factors, and JAK2 V617F mutation status. 

The clinical utility of this calculator is to guide clinicians in making treatment decisions, such as the initiation of cytoreductive therapy or low-dose aspirin, and to provide patients with a prognosis regarding their risk of thrombosis. 

There are no specific exclusion criteria for the use of the Revised IPSET score, but it should be noted that it is only applicable to patients with a confirmed diagnosis of essential thrombocythemia. It is not intended for use in patients with other myeloproliferative disorders or in those without a definitive diagnosis.

Revised IPSET score for essential thrombocythemia