Table 2.

Multiphase hazard model of pump thrombosis

Factor	Coefficient ± SE	P
Early phase
Higher LDHa	−13 ± 2.0	<0.0001
Recent date of implantb	0.64 ± 0.25	0.009
Late phase
Higher LDHc	0.45 ± 0.081	<0.0001
Earlier date of implantd	−2.6 ± 1.3	0.06

The hazard model separates early phase, the time of implant to approximately 12 months post‐implant, and late phase, approximately 12 months post‐implant to removal of the device for any reason or death. Date of implant refers to the calendar date of surgery, with more recent years increasing risk of pump thrombosis in the early phase. LDH, lactate dehydrogenase; SE, standard error.

^a[440/(LDH + 352)], inverse transformation.

^b[(Date of implant, expressed as interval between 01/01/2004 and implant)/7]³, cubed transformation.

^c[(LDH + 352)/440]², squared transformation.

^dLog[(date of implant, expressed as interval between 01/01/2004 and implant)], logarithmic transformation.