Table 2.

Clinical candidate predictors for model development with the number of coefficients to be estimated. The sum of the number of coefficients to be estimated was based on a sample size calculation for clinical prediction models

Nr	Variable type	Variable name	Level of measurement	Coefficients	Comments
1	Donor	Age	Continuous	3	Restricted cubic splines with 3 knots
2	Donor	Donor type (DCD, DBD)	Binary	1	Donation after circulatory death (DCD) or brain death (DBD)
3	Donor	History of diabetes	Binary	1
4	Donor	History of hypertension	Binary	1
5	Donor	eGFR on admission	Continuous	1	Estimated glomerular filtration rate
6	Donor	eGFR at allocation	Continuous	1
7	Donor	Resuscitation	Binary	1	Donor was reanimated or not
8	Donor	Cause of death	Categorial	2	Using the 2 most common causes
9	Transplantation	Anti-HLA: DSA	Binary	1	Presence of donor-specific antibodies
10	Transplantation	HLA mismatches	Count	1	Human leukocyte antigen mismatches; number between 0 and 6
11	Transplantation	Retransplantation	Binary	1	Whether recipient was retransplanted
12	Recipient	Age	Continuous	1
13	Recipient	Cardiovascular disease	Binary	1
14	Recipient	History of diabetes	Binary	1
15	Recipient	BMI	Continuous	1	Body mass index
16	Recipient	Pre-transplant dialysis	Continuous	1	Time on dialysis
			Total:	19