Table 2.

Donor baseline characteristics for the study cohorts.

	N	Ext. validation 2017–2018 N = 4750	Test 2014–2016 N = 6120	Train/val. 1987–2013 N = 31,315	Test statistic
Donor age (yrs)*,†	42,185	24 31 40 33 ± 11	23 31 41 32 ± 11	21 30 42 32 ± 12	F2 42182 = 18, P < 0.0012
Donor female gender*	42,185	30%1443⁄4750	30%1828⁄6120	29%9214⁄31,315	χ22 = 2.1, P = 0.361
Donor height (cm)*	42,144	168.0 175.0 180.3 174.0 ± 9.6	167.6 175.0 180.3 173.8 ± 9.6	167.6 175.3 182.9 174.6 ± 9.5	F2 42141 = 19, P < 0.0012
Donor weight (kg)*	42,179	70 81 95 84 ± 19	70 80 93 83 ± 20	68 79 90 81 ± 18	F2 42176 = 69, P < 0.0012
Donor ABO blood type*	42,184				χ26 = 7.7, P = 0.261
A		36.7%1745⁄4750	35.3%2163⁄6120	36.4%11,413⁄31,314
AB		2.1%99⁄4750	2.5%154⁄6120	2.3%706⁄31,314
B		10.9%520⁄4750	11.3%690⁄6120	10.5%3295⁄31,314
O		50.2%2386⁄4750	50.9%3113⁄6120	50.8%15,900⁄31,314
Donor cause of death*	42,149				χ28 = 2669, P < 0.0011
Anoxia		38.2%1813⁄4748	29.8%1823⁄6118	12.3%3850⁄31,283
Cerebrovascular/stroke		14.8%703⁄4748	19.1%1166⁄6118	25.6%8000⁄31,283
CNS tumor		0.5%23⁄4748	0.3%21⁄6118	1.0%313⁄31,283
Head trauma		44.6%2119⁄4748	48.6%2971⁄6118	59.3%18,544⁄31,283
Other		1.9%90⁄4748	2.2%137⁄6118	1.8%576⁄31,283
Ischemic time (min)*,†	40,394	138 184 223 183 ± 64	143 186 227 187 ± 62	146 188 229 190 ± 63	F2 40391 = 23, P < 0.0012
Recipient-donor height ratio*	42,037	0.963 1.000 1.036 1.000 ± 0.056	0.967 1.000 1.040 1.002 ± 0.057	0.958 1.000 1.036 0.998 ± 0.061	F2 42034 = 16, P < 0.0012
Recipient-donor weight ratio*	42,086	0.87 1.03 1.18 1.03 ± 0.23	0.88 1.02 1.17 1.03 ± 0.22	0.88 1.02 1.16 1.02 ± 0.21	F2 42083 = 2.6, P = 0.0712

a b c represents the lower quartile a, the median b, and the upper quartile c for continuous variables. x ± s represents X ± 1 SD. N is the number of non-missing values. Variables included in * IHTSA, ^# IMPACT, and ^† PRN model. CNS, Central nervous system tumours. Tests used: ¹Pearson test; ²Kruskal–Wallis test.