Table 2. Incidence of suspected heparin induced thrombocytopenia (HIT) and confirmed HIT in patients on extracorporeal membrane oxygenation (ECMO), pooled from the five retrospective studies and one case series.

Patients on ECMO	Pooled value (%) [95% CI]	No. of studies	No. of patients (n/N)	I2 (%)
HIT suspected	83 [47–96]	6	187/309	94*
HIT confirmed	17 [5–48]	6	24/309	86*

*, heterogeneity P<0.05 (significant data heterogeneity present).