Table 1.

Predefined clinical and serologic values used to define likelihood of HIT

HIT ELISA (OD)	Clinical score (4Ts value)
	0-3 (low)	4-5 (intermediate)	6-8 (high)
≤0.3 or <0.4	Negative (276)	Negative (74)	Negative (10)
>0.3 (or ≥0.4) to <1.0	Negative (5)	Negative (15)	Indeterminate (3)*
1.000 to <2.0	Negative (3)	Indeterminate (6)*	Positive (10)
≥2.0	Indeterminate (0)*	Positive (3)	Positive (4)

OD, optical density.

^*Indeterminate results were considered disease negative in the primary analysis. In a sensitivity analysis (presented in the supplemental Materials), indeterminate results were considered disease positive. Number in parenthesis indicates the number of patients within each group. These criteria were defined before study initiation.