The 4 T's Score 계산기 (for the diagnosis of Heparin-Induced Thrombocytopenia, HIT)

Heparin-Induced Thrombocytopenia (HIT) 임상적 진단을 위한 4T score 계산기
해당 항목을 클릭하시면 자동으로 계산됩니다.

Platelet count fall >50% and platelet nadir ≥20 × 10⁹/L (2점)

Platelet count fall 30%-50% or platelet nadir 10-19 × 10⁹/L (1점)

Platelet count fall ＜30% or platelet nadir ＜10 × 10⁹/L (0점)

Clear onset between days 5 and 10 OR platelet fall ≤1 day (prior heparin exposure within 30 days) (2점)

Consistent with days 5-10 fall, but not clear (e.g. missing platelet counts) OR onset after day 10 or fall ≤1 day (prior heparin exposure 30-100 days ago) (1점)

Platelet count fall ＜4 days without recent heparin exposure (0점)

New thrombosis (confirmed) OR skin necrosis at heparin injection sites or acute systemic reaction after intravenous heparin bolus (2점)

Progressive or recurrent thrombosis or nonnecrotizing (erythematous) skin lesions or suspected thrombosis (not proven) (1점)

None (0점)

None apparent (2점)

Possible (1점)

Definite (0점)

≥6점: High probability of HIT
4-5점: Intermediate probability of HIT
≤3점: Low probability of HIT

Reference :
Lo GK, Juhl D, Warkentin TE, Sigouin CS, Eichler P, Greinacher A. Evaluation of pretest clinical score (4 T’s) for the diagnosis of heparin-induced thrombocytopenia in two clinical settings. J Thromb Haemost. 2006 Apr;4(4):759-65. doi: 10.1111/j.1538-7836.2006.01787.x. PMID: 16634737.

The 4 T’s Score 계산기 (for the diagnosis of Heparin-Induced Thrombocytopenia, HIT)