Table 2.

The equation parameters of each prediction model to estimate the 10‐year risk of donor mortality (a), recipient mortality (b) and graft loss (c).

(a)

Donor mortality model

The hypothetical donor profile (the ‘Individual Example Value’ column) assumes a 48‐year‐old donor candidate who is a nonsmoker, with a total cholesterol of 6.5 mmol/l, and a serum creatinine of 71 µmol/l. Calculation of the 10‐ and 20‐year risk estimate for donor mortality given this hypothetical donor can be done following the three steps as described above: First and second step: Compute the individual linear predictor by (0.1120 × 48) + (0.43 × 0) + (−0.1078 × 6.5) + (0.0182 × 71) = 5.9664. Third step for 10 year risk: $1-0.{9921402}^{exp\left(5.9664-7.2449\right)}$ and results in a calculated 0.22% risk of donor death within 10 years. Third step for 20 year risk: $1-0.{9534074}^{\mathit{exp}\left(5.9664-7.2449\right)}$ and results in a calculated 1.3% risk of donor death within 20 years

(a) Predictor	Coefficient	Individual example value	Coefficient × individual example value	Range for continuous predictors
Donor age (years)	0.1120	48	5.3752	19–82
Current smoking status Smoker = 1 vs. non‐smoker = 0	0.4300	0	0	–
Total cholesterol (mmol/l)	−0.1078	6.5	−0.7008	1.5–12.5
Serum creatinine (µmol/l)	0.0182	71	1.2920	35–160
Individual linear predictor			5.9664
Mean linear predictor			7.2449
Baseline survival for 10‐year prediction			0.9921402
Estimated 10‐year mortality risk			0.22%
Baseline survival for 20‐year prediction			0.9534074
Estimated 20‐year mortality risk			1.3%

(b)

Recipient mortality model

The hypothetical recipient profile (the ‘Individual Example Value’ column) assumes a 60‐year‐old male transplant candidate who is transplanted preemptively or on peritoneal dialysis, with a glomerulonephritis as primary renal disease, with no previous cerebrovascular or peripheral arterial disease, and a full match in class II HLA antibodies (DR) with his potential living donor. Calculation of the 10‐year risk estimate for recipient mortality given this hypothetical recipient can be done following the three steps as described above: First and second step: Compute the individual linear predictor by (0.0663 × 60) + (0.3669 × 0) + (−0.6636 × 0) + (−0.7721 × 0) + (−0.8756 × 1) + (0.4280 × 0) × (0.3365 × 0) + (−0.1904 × 1) + (0.1451 × 0) = 2.9104. Third step: $1-0.{8517}^{\mathit{exp}\left(2.9104-2.9416\right)}$ and results in a calculated 14.4% risk of recipient death within 10 years

(b) Predictor	Coefficient	Individual example value	Coefficient × value	Range for continuous predictors
Recipient age (years)	0.0663	60	3.9764	18–78
Dialysis vintage Hemodialysis = 1 vs peritoneal dialysis or preemptive transplantation = 0	0.3669	0	0	–
Primary renal disease* diabetic nephropathy = 0 vs else = 1	−0.6636	0	0	–
Primary renal disease diabetic nephropathy = 0 vs vascular nephropathy = 1	−0.7721	0	0	–
Primary renal disease diabetic nephropathy = 0 vs glomerulonephritis = 1	−0.8756	1	−0.8756	–
Cerebrovascular disease Yes = 1 vs no = 0	0.4280	0	0	–
Peripheral vascular disease Yes = 1 vs no = 0	0.3365	0	0	–
Recipient sex male = 1 vs female = 0	−0.1904	1	−0.1904	–
Sum of HLA mismatch in DR	0.1451	0	0	0–2
Individual linear predictor			2.9104
Mean linear predictor			2.9416
Baseline survival			0.8517
Estimated 10‐year risk			14.4%

(c)

Graft loss model

For the same hypothetical donor recipient pair, the 10‐year risk estimate for graft loss can be calculated assuming a sum of mismatch of HLA class I (AB) antibodies of 2, and no previous cardiovascular disease: First step: use the linear predictor of the donor (5.9664) as calculated in (a). Second step: Compute the individual linear predictor by (0.2656 × 5.9664) + (−0.0299 × 60) + (0.2245 × 0) + (0.6319 × 0) + (−0.1270 × 2) + (−0.7848 × 0) + (0.4925 × 0) = −0.4633. Third step: $1-0.{8806}^{\mathit{exp}\left(-0.4633\text{to}0.8306\right)}$ and results in a calculated 3.4% risk of graft loss within 10 years

(c) Predictor	Coefficient	Individual example value	Coefficient × value	Range for continuous predictors
Linear predictor for donor (from a)	0.2656	5.9664	1.5846
Recipient age (years)	−0.0299	60	−1.7938	18–78
Dialysis vintage Haemodialysis = 1 vs peritoneal dialysis or preemptive transplantation = 0	0.2245	0	0	–
Sum of HLA mismatch in DR	0.6319	0	0	0–2
Sum of HLA mismatch in A,B	−0.1270	2	−0.2541	0–4
Peripheral vascular disease Yes = 1 vs no = 0	−0.7848	0	0	–
Cardiovascular disease Yes = 1 vs no = 0	0.4925	0	0	–
Individual linear predictor			−0.4633
Mean linear predictor			0.8306
Baseline survival			0.8806
Estimated 10‐year risk			3.4%

Each table also includes a specific example of a hypothetical donor/recipient pair (the ‘Individual Example Value’) to illustrate the calculation procedure. Coefficients of all predictors, as well as the mean linear predictors, were multiplied with the appropriate shrinkage factor. Calendar year of donation/transplantation was fixed at the value for 2007, referring to the latest date of a donation/transplantation in the database, and was accounted for in the respective mean linear predictor. A donor/recipient profile can be inserted in the ‘Individual Example Value’ column. Calculation of the 10‐year risk estimate for the respective event given the inserted donor/recipient values can be done in three steps as follows: First, the individual example values are multiplied with the respective optimism‐corrected coefficients that were derived from the cox model equation and are provided in the column ‘Coefficient’. The column ‘Coefficient × Individual Example Value’ provides the results of this multiplication for an illustrative example in all tables. Second, the sum of the ‘Coefficient × Individual Example Value’ is then calculated for each individual to get the ‘Individual Linear Predictor’. Third, the estimated 10‐year risk of the respective event is then calculated as 1 minus the survival rate at 10 years (‘Baseline Survival’ in the table), raised to the power of the exponent of the ‘Individual Linear Predictor’ minus the ‘Mean Linear Predictor’ or, in equation form: $1-S_{10}^{exp(individualLP-meanLP)}$.

Bold values indicate calculated risks for the hypothetical donor and recipient pair.

^*Primary renal disease is a categorical predictor with four groups, diabetic nephropathy, vascular nephropathy, glomerulonephritis and else. Diabetic nephropathy was used as reference group.