Effect of transplant center volume on post-transplant survival in patients listed for simultaneous liver and kidney transplantation

Table 2 Hazard model of survival after liver transplant alone or simultaneous liver-kidney transplant in patients listed for liver and kidney transplant

Variable1	HR	95%CI	P value
Transplant received
SLK	ref.
LTA	2.85	(2.21, 3.66)	< 0.001
Transplant center SLK volume2
Interaction with receiving LTA vs SLK	0.97	(0.95, 0.99)	0.010
Age (yr)	1.01	(1.01, 1.02)	< 0.001
Male	1.08	(0.94, 1.24)	0.285
Race
White	ref.
Black	1.17	(0.98, 1.39)	0.089
Other	0.79	(0.66, 0.94)	0.007
Etiology of liver disease
Viral	ref.
Cryptogenic	0.77	(0.61, 0.98)	0.033
Autoimmune	0.57	(0.41, 0.79)	0.001
NASH	0.79	(0.63, 1.01)	0.060
Alcoholic	0.65	(0.54, 0.77)	< 0.001
HCC	1.04	(0.83, 1.30)	0.721
AHN	1.10	(0.75, 1.63)	0.621
Other	0.77	(0.62, 0.97)	0.024
Diabetes	1.23	(1.08, 1.40)	0.002
Dialysis	1.41	(1.19, 1.67)	< 0.001
BMI (kg/m2)	0.98	(0.97, 0.99)	0.003
Serum creatinine (mg/dL)	0.97	(0.93, 1.01)	0.092
Bilirubin (mg/dL)	1.00	(0.98, 1.01)	0.394
Albumin (mg/dL)	0.88	(0.81, 0.96)	0.004
INR	0.92	(0.81, 1.05)	0.224
MELD score	1.00	(0.99, 1.02)	0.661
eGFR	1.00	(1.00, 1.01)	0.622
Hepatic encephalopathy on wait list	1.10	(0.94, 1.28)	0.221
Liver allograft cold ischemia time	1.00	(0.98, 1.02)	0.811
Year of transplant	0.98	(0.96, 1.00)	0.107

¹Covariates assessed at wait listing, apart from center volume over study period, hepatic encephalopathy on the wait list, liver allograft cold ischemic time, and year of transplant;

²Total number of SLK performed over study period (2/2002-12/2015), centered at 30 procedures, and divided by 10. Multivariable Cox proportional hazards model, with the baseline hazard stratified on the transplant center, of survival after liver transplant alone or simultaneous liver-kidney transplant among patients listed for liver and kidney transplant in 2002-2015 (n = 4257). HR: Hazard ratio; CI: Confidence interval; SLK: Simultaneous liver-kidney transplant; LTA: Liver transplant alone; NASH: Non-alcoholic steatohepatitis; HCC: Hepatocellular carcinoma; AHN: Acute hepatic necrosis; BMI: Body mass index; INR: International normalized ratio; MELD: Model for end-stage liver disease; eGFR: Estimated glomerular filtration rate.