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Table 1 Patient and transplant characteristics

From: Associations with kidney transplant survival and eGFR decline in children and young adults in the United Kingdom: a retrospective cohort study

Variable

Total n

n

%

Male sex

5121

3107

60.7

Ethnic group

 White

4918

3955

80.4

 Asian

579

11.8

 Black

215

4.4

 Mixed/other

169

3.4

Primary kidney disease groupa

 Glomerular disease

5065

1467

29.0

 Systemic diseases affecting the kidney

304

6.0

 Familial/hereditary nephropathies

593

11.7

 Tubulointerstitial disease

1808

35.7

 Miscellaneous kidney disorders

893

17.6

Late presentationb

3366

867

25.8

Age when first seen (years) (median, IQR)

3389

13.1

2.7, 20.0

Age at KRT start (years) (median, IQR)

5085

19.1

12.9, 24.1

Years to KRT start from first nephrology review (median, IQR)

3370

2.0

0.2. 5.4

Tertiles of year started KRT (median, IQR)

5085

2006

2001, 2009

 1983–2003

5085

1936

38.1

 2004–2008

1607

31.6

 2009–2014

1542

30.3

Start modality

 Haemodialysis

5102

2011

39.4

 Peritoneal dialysis

1839

36.0

 Transplant

1252

24.5

 Age at transfer (years) (median, IQR)

1455

18

17.4, 18.5

Died

5121

260

5.1

 Age at death (years) (median, IQR)

260

27.6

20.3, 32.3

Transplanted during study period

 Graft 1

4750

4377

85.5

 Graft 2

 

371

7.2

 Graft 3

 

2

0.04

 Re-transplanted during study period

 Graft 2

371

369

7.2

 Graft 3

 

2

0.04

Time from listing to transplant (years) (median, IQR)

4416

0.8

0.3, 1.8

Year of transplant

 1998–2003

5121

1291

25.2

 2004–2009

 

1930

37.7

 2010–2014

 

1900

37.1

Donor type

 Live donation

5121

2462

48.1

 Donation after brainstem death

 

2356

46.0

 Donation after circulatory death

 

303

5.9

Donor age (years) (median, IQR)

5115

41

27, 49

Cold ischaemic time (hours) (median, IQR)

4651

9.3

2.8, 16.3

Calculated reaction frequency (%) (median, IQR)c

5118

0

0, 12

HLA mismatch groupd

 0 mismatches

5120

544

10.6

 [0 HLA-DR and 0/1 HLA-B] mismatches

2016

39.4

 [0 HLA-DR and 2 HLA-B] or [1 HLA-DR and 0/1 HLA-B] mismatches

2272

44.4

 [1 HLA-DR and 2 HLA-B] or [2 HLA-DR] mismatches

288

5.6

First eGFR (mL/min/1.73m2) (mean, SD)e

4882

62

23

Rate of eGFR change (mL/min/1.73m2/year) (mean, SD)

4487

−3.14

7.69

Graft failure

5111

1376

26.9

 Follow up time (years) (median, IQR)

5111

7.0

4.0, 10.9

 Time to event (years) (median, IQR)

1376

4.2

1.5, 7.6

Patient death

4750

238

5.0

 Follow up time (years) (median, IQR)

4750

8.8

5.1, 13.0

 Time to event (years) (median, IQR)

238

6.6

3.0, 10.6

Age at event (mean, SD)

5111

27.5

8.7

  1. IQR interquartile range, KRT kidney replacement therapy, SD standard deviation, HLA human leucocyte antigen, eGFR estimated glomerular filtration rate
  2. Ages are based on dates of birth rounded to mid-month
  3. aPrimary kidney disease was using a 2012 European coding system [27]. The pediatric diagnosis was used where discordant between pediatric and adult databases [28]
  4. bLate presentation defined as ≤90 days from first nephrology review to RRT start
  5. cCalculated reaction frequency is defined as the percentage of ABO-identical patients within the donor pool that are HLA incompatible with an individual patient and is dependent on blood group and antibodies [29]
  6. dHLA mismatch groups were derived from the UK 2006 National Kidney Allocation scheme [17]. The HLA-A:B:DR mismatches included in each group are as follows:
  7. [0 HLA-DR and 0/1 HLA-B] - 1:0:0, 0:1:0, 1:1:0, 2:0:0, 2:1:0
  8. [0 HLA-DR and 2 HLA-B] or [1 HLA-DR and 0/1 HLA-B]
  9. 0:2:0, 1:2:0, 2:2:0, 0:0:1, 1:0:1, 2:0:1, 0:1:1, 1:1:1, 2:1:1
  10. [1 HLA-DR and 2 HLA-B] or [2 HLA-DR]
  11. 0:2:1, 1:2:1, 2:2:1, 0:0:2, 1:0:2, 2:0:2, 0:1:2, 1:1:2, 2:1:2, 0:2:2, 1:2:2, 2:2:2.
  12. eeGFR post-transplant calculated from the first biochemical data recorded by the UK Renal Registry following transplantation. Returns are annual for paediatrics and quarterly for adults