Table 1. 4Ts scoring system³⁸.

	Score
	0	1	2
Thrombocytopenia: Percentage of platelet count	<30% fall OR Nadir <10 × 109/L.	30–50%% fall or Nadir 10-19 × 109/L.	>50% fall or Nadir ≥20 × 109/L.
Time / onset of thrombocytopenia	<Day4 with no recent heparin exposure.	>Day 10 OR <Day 1 with heparin exposure between 31–100 days OR Unknown onset.	>Day 5–10 OR Day 1 with heparin exposure <30 days.
Thrombosis / complications	No	Progressive or recurrent thrombosis OR suspected thrombosis OR skin erythema.	Proven new thrombus OR skin necrosis OR acute systemic reaction after UFH bolus.
Other causes of Thrombocytopenia	Proven	Possible	Not proven