Machine perfusion distribution across clinical phenotypes in kidney transplantation: A national cohort study using unsupervised clustering

Table 6 Full cohort features standardized mean differences by cluster

Characteristic	Cluster 1 (n = 2797)	Cluster 2 (n = 2826)	Cluster 3 (n = 2370)	Cluster 4 (n = 1854)	Cluster 5 (n = 2402)	Cluster 6 (n = 3655)
Recipient age	-0.53127	0.890174	-0.37819	0.263441	-0.74394	0.652855
Recipient BMI	-0.05273	0.36501	-0.0351	0.050277	-0.36817	0.051705
Recipient sex
Female	0.046416	-0.37198	-0.0387	0.057848	0.354276	-0.07143
Male	-0.04642	0.371976	0.038704	-0.05785	-0.35428	0.07143
Recipient ABO blood group
A	0.029565	-0.00315	0.072027	-0.09341	-0.03266	0.026294
AB	0.065362	0.025794	-0.06948	-0.01586	0.034174	-0.04917
B	-0.03387	-0.03848	-0.13933	0.186659	0.030704	-0.02611
O	-0.03678	0.017429	0.048903	-0.03802	-0.00484	0.013025
Recipient ethnicity
Asian	-0.06851	-0.13465	-0.33311	0.28277	0.195452	-0.00306
Black	0.016715	-0.00709	-0.24634	0.227795	0.001301	-0.03807
White	0.047113	0.119418	0.451491	-0.41774	-0.17413	0.028319
Recipient diabetes	-0.15378	0.332122	-0.16925	0.148745	-0.3113	0.056299
Recipient positive CMV status	-0.076	-0.037	-0.2564	0.270441	0.030052	0.075713
Dialysis status at registration
Hemodialysis	0.086843	0.213382	-0.28001	0.112707	-0.10092	-0.03491
Not	-0.11826	-0.25069	0.325769	-0.14902	0.111091	0.060756
Peritoneal	0.032607	0.024453	-0.05462	0.035873	-0.00844	-0.03204
Dialysis at transplant	0.097919	0.171868	-0.33548	0.107925	-0.00066	0.004394
Type of dialysis at transplant
Hemodialysis	-0.01072	0.059037	-0.13685	0.044986	0.001169	0.047248
Not	0.108832	-0.00796	-0.0172	-0.02224	-0.09087	-0.01846
Peritoneal	-0.01332	-0.05813	0.140569	-0.04158	0.011823	-0.04447
Donor organ
Left kidney	-0.09442	0.06469	-0.0406	0.080451	-0.14511	0.133529
Right kidney	0.094421	-0.06469	0.0406	-0.08045	0.145105	-0.13353
Highly sensitised status flag	-0.1051	-0.25405	-0.05252	0.278585	0.137113	-0.10495
Waiting list time	0.205676	0.184614	-0.68461	0.155021	0.029542	0.033337
Recipient deprivation group
Quartile 1 most deprived	-0.13673	0.125214	0.135129	-0.11206	-0.14645	0.114791
Quartile 2 second most deprived	-0.0373	0.028104	0.089469	-0.04483	-0.08356	0.043987
Quartile 3 second least deprived	0.086139	-0.01602	-0.12754	0.046672	0.05857	-0.05414
Quartile 4 least deprived	0.078204	-0.14132	-0.10361	0.102159	0.15673	-0.10738
Donor age	-0.77397	1.151346	0.059862	-0.07552	-1.07416	0.922674
Donor BMI	-0.22905	0.335247	0.015342	-0.0657	-0.29796	0.217399
Donor sex
Female	-0.11263	0.072835	0.134812	-0.08067	-0.13794	0.120255
Male	0.112627	-0.07283	-0.13481	0.080672	0.137942	-0.12026
Donor ABO blood group
A	0.039102	0.016699	0.077042	-0.13229	-0.02753	0.024879
AB	0.060752	0.008323	-0.11541	-0.00955	0.054528	-0.01621
B	-0.01511	-0.00672	-0.17588	0.143325	0.030238	0.001161
O	-0.05233	-0.01535	0.059672	0.039371	-0.01204	-0.01951
Donor ethnicity
Asian	0.000514	0.038364	-0.0821	0.024941	0.0001	0.010053
Black	0.00643	-0.01655	-0.01361	0.030552	0.015678	-0.02584
White	-0.00408	-0.02369	0.075358	-0.03827	-0.00908	0.005607
Donor positive CMV status	-0.12041	0.098053	0.021299	-0.06591	-0.06611	0.132632
Donor positive EBV status	0.029951	0.081959	0.001328	0.019402	-0.13784	0.02228
Donor positive toxoplasmosis status	-0.13706	0.095696	0.010196	-0.01706	-0.06299	0.098
Donor cardiac disease	-0.29989	0.452731	-0.07382	-0.09806	-0.3734	0.210295
Donor diabetes	-0.23863	0.303632	-0.02393	-0.02724	-0.25273	0.120616
Donor family history of diabetes	0.117106	-0.06168	-0.04535	0.05733	0.078348	-0.15243
Donor history of drug abuse	0.81861	-0.42472	-0.48799	0.339628	0.105875	-0.68139
Donor hypertension	-0.59749	0.75056	-0.00457	-0.09059	-0.70759	0.419629
Donor smoker	0.386329	-0.04618	-0.28052	0.233903	0.062836	-0.32145
Donor history of UTI	-0.02595	0.051784	-0.0268	-0.00334	-0.05092	0.049397
Donor allergy	0.182199	0.349431	-0.23512	0.17585	-0.37885	-0.12589
Donor creatinine at retrieval	0.111216	-0.20679	-0.04272	0.058724	0.126459	-0.05897
Donor type
DBD	0.163396	-0.21653	0.322543	-0.15502	0.161577	-0.26117
DCD	-0.1634	0.216534	-0.32254	0.155025	-0.16158	0.261166
Donor cause of death
Neurological	0.079257	0.188412	-0.01799	0.032678	-0.25947	0.031494
Other	-0.07926	-0.18841	0.017991	-0.03268	0.259472	-0.03149
Cold ischemia time	0.034621	0.064709	-0.1487	0.110151	-0.03088	-0.03307
Perfusate used
HTK	0.215541	0.290157	-0.37809	0.297393	-0.41002	-0.3985
Marshalls	-0.20981	0.069047	-0.01459	-0.0697	-0.08986	0.273508
Wisconsin	0.024312	-0.25256	0.202352	-0.14489	0.288148	-0.0685
Perfusion quality
Fair	-0.09903	0.066815	-0.02273	0.053659	-0.05518	0.043223
Good	0.124324	-0.07958	0.038627	-0.05322	0.067024	-0.081
Poor	-0.0704	0.039988	-0.03226	0.015022	-0.03558	0.071809
Machine perfusion type
HMP	-0.16465	-0.10792	0.072853	-0.13631	0.066932	0.165752
NMP	-0.02219	-0.00674	-0.03713	0.026516	0.005664	0.028618
SCS	0.139758	0.087785	-0.0411	0.083732	-0.05858	-0.15598
Donor homozygous at A locus	-0.02882	-0.03397	0.331391	-0.14094	-0.08519	-0.08234
Donor homozygous at B locus	0.018333	-0.00219	0.324462	-0.32254	-0.05012	-0.07189
Donor homozygous at DR locus	-0.07049	-0.05484	0.384054	-0.34321	0.018206	-0.03753
Recipient homozygous at A locus	-0.11426	-0.12039	-0.26716	0.185844	0.20061	0.06497
Recipient homozygous at B locus	-0.24938	-0.25056	-0.36106	0.442481	0.216542	0.018343
Recipient homozygous at DR locus	-0.3925	-0.3688	-0.4553	0.514814	0.316519	0.132615
Number of mismatches at A locus
One	0.100524	0.107959	-0.19918	-0.046	-0.00287	0.037924
Two	-0.04103	-0.02375	-0.61386	0.245613	0.214416	0.138909
Zero	-0.08528	-0.11969	0.865188	-0.28684	-0.30846	-0.25372
Number of mismatches at B locus
One	0.194076	0.181726	-0.21583	-1.02907	0.522414	0.361438
Two	-0.43557	-0.20574	-0.80177	1.61737	-0.26989	-0.11265
Zero	0.168862	-0.01822	0.860889	-0.57823	-0.41804	-0.39044
Number of mismatches at DR locus
One	0.156213	0.362725	-1.58327	-0.08453	0.169242	0.572884
Two	-0.49823	-0.29474	-0.53587	1.400915	-0.41166	-0.3312
Zero	0.083765	-0.20624	2.088466	-1.29858	0.038214	-0.39782
HLA mismatch group
(0 DR and 2B) OR (1 DR and 1/0 B)	0.320803	0.492691	-1.5359	-0.88766	0.35718	0.817322
(1 DR and 2 B) OR (2 DR)	-0.64264	-0.32933	-0.73181	2.732471	-0.5118	-0.36669
0 DR and 1/0 B	0.200285	-0.13652	0.942319	-1.01767	0.132115	-0.42344
0 Mismatches	-0.29107	-0.33901	1.013344	-0.3991	-0.3991	-0.3991
Initial graft function
DGF	-0.11953	0.293189	-0.1664	0.075526	-0.21589	0.094297
Immediate	0.107333	-0.35624	0.207118	-0.087	0.260541	-0.08576
PNF	0.019437	0.177065	-0.13987	0.038363	-0.15666	-0.01597
Predniscolone/predniscone immunosuppression 3 months post-transplant
No	-0.10243	-0.02439	0.089443	-0.0981	0.005436	0.123103
Yes	0.102431	0.024386	-0.08944	0.098099	-0.00544	-0.1231
Graft status
Died functioning	-0.25092	0.067352	-0.02856	-0.02329	-0.15542	0.314832
Died unknown function	-0.04474	0.055994	-0.039	0.010615	-0.01671	0.011187
Failed	-0.18583	0.234386	0.023866	-0.09706	-0.13882	0.114523
Functioning	0.330622	-0.24579	0.006453	0.089744	0.222438	-0.33668
Allocation matchability score	-0.82615	-0.91113	-0.48134	0.939133	0.94143	0.608976
Serum creatinine (umol/L) at 3 months post-transplant	-0.55205	1.076702	-0.00929	-0.20292	-1.05008	0.27868
Serum creatinine (umol/L) at 12 months post-transplant	-0.54517	1.001822	0.035808	-0.20997	-0.97139	0.28784
Follow-up time	-1.02083	-1.36537	1.02637	-1.03852	1.304328	0.609898
Transplant year
2014	-0.46973	-0.40766	0.318161	-0.41243	0.36776	0.215761
2015	-0.44461	-0.3679	0.280245	-0.36841	0.317711	0.249368
2016	-0.43155	-0.31821	0.318755	-0.35172	0.25152	0.249478
2017	-0.35466	-0.2451	0.278868	-0.36176	0.238236	0.233183
2018	-0.14226	-0.11021	0.065559	-0.22613	0.162749	0.19049
2019	0.031142	-0.00751	-0.11104	0.1739	-0.14187	0.03025
2020	0.29756	0.11046	-0.33259	0.309795	-0.32021	-0.2833
2021	0.37828	0.319815	-0.4093	0.228833	-0.46416	-0.41834
2022	0.368105	0.342109	-0.43481	0.233157	-0.46783	-0.46145
2023	0.262064	0.285086	-0.3182	0.121005	-0.34658	-0.33995
2024	0.066904	0.161389	-0.30486	0.355243	-0.30492	-0.30949
Kidney used by local centre
No	0.358659	0.266388	-0.07062	0.248008	-0.23235	-0.46553
Yes	-0.35866	-0.26639	0.070616	-0.24801	0.232346	0.465532

BMI: Body mass index; UTI: Urinary tract infection; DBD: Donation after brain death; DCD: Donation after cardiac death; HTK: Histidine-tryptophan-ketoglutarate solution; HMP: Hypothermic machine perfusion; NMP: Normothermic machine perfusion; HLA: Human leukocyte antigen; DGF: Delayed graft function; PNF: Primary non-function.