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

Table 2 Multivariable Cox proportional hazards examining associations with death-censored kidney transplant failure in UK patients transplanted under 30 years of age

Variable	Hazard Ratio	95% confidence interval		p-value
Variable	Hazard Ratio	Lower	Upper	p-value
Female sex	1.13	1.00	1.28	0.049
Live donor (cf. deceased donor)	0.86	0.76	0.97	0.01
Human Leucocyte Antigen mismatches^a [One DR & two B locus OR two DR locus mismatches]	1.50	1.19	1.89	0.001
Higher first reported eGFR post-transplant^b (per 10 mL/min/1.73 m²)	0.82	0.79	0.86	< 0.0001
Glomerular diseases^{c, d}	1.30	1.14	1.48	< 0.0001
Age group (cf. 25–29 years)^e
2–4	0.73	0.44	1.23	0.2
5–9	0.49	0.33	0.73	< 0.0001
10–14	0.93	0.73	1.17	0.5
15–19	1.54	1.29	1.83	< 0.0001
20–24	1.41	1.20	1.67	< 0.0001
30–34	0.75	0.60	0.94	0.01
35–39	0.78	0.54	1.11	0.2
40–44	0.82	0.39	1.70	0.6
Ethnicity (compared to White)
Asian	1.02	0.83	1.24	0.9
Black	1.51	1.15	1.97	0.003
Mixed/Other	1.02	0.71	1.44	0.9
Year of transplant (cf. 1998–2005)
2006–2010	1.05	0.91	1.21	0.5
2011–2014	1.17	0.97	1.42	0.1

Stratified by transplant number in the study period. Standard error adjusted for 4392 clusters
Live donation by ethnic group was as follows: White, 49%; Asian, 32%, Black, 37%; Mixed/Other, 48%
^aHLA mismatch groups were derived from the UK 2006 National Kidney Allocation scheme [17]
^beGFR 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
^cPrimary kidney disease was using a 2012 European coding system [27]. The pediatric diagnosis was used where discordant between pediatric and adult databases [28]
^dThere was non-proportionality over time between those with and without glomerular diseases. Piecewise Cox regression analyses split at 1 year showed similar effects for glomerular diseases [≤1 year HR 2.05 (1.34, 3.14), p = 0.001; > 1 year HR 1.24 (1.08, 1.43), p = 0.002) and no effect on other HRs; this model presents the overall HR for the entire follow-up period
^eThe 45–49-year age group is suppressed due to small numbers (n = 8)

ISSN: 1471-2369