A validation study of the 4-variable and 8-variable kidney failure risk equation in transplant recipients in the United Kingdom

Table 1 Characteristics of the study cohort 1-year post-transplant

Variable	All patients (n = 415)	Living donor recipient (n = 97)	Deceased donor recipient (n = 318)	p-value^
Age, years	49.8 (38.9–59.6)	40.0 (30.7–53.3)	51.2 (41.5–62.4)	< 0.001
Male, n (%)	244 (59)	51 (53)	174 (61)	0.155
Caucasian, n (%)	352 (88)	97 (100)	311 (98)	0.141
Hypertension, n (%)	383 (92)	90 (93)	293 (92)	0.835
Diabetes mellitus, n (%)	48 (12)	6 (6)	42 (13)	0.058
Primary renal disease
Glomerulonephritis, n (%)	120 (29)	35 (36)	85 (27)	0.075
ADPKD, n (%)	55 (13)	14 (14)	41 (13)	0.695
Diabetic nephropathy, n (%)	44 (11)	6 (6)	38 (12)	0.106
Hypertensive nephropathy, n (%)	21 (5)	5 (5)	16 (5)	0.961
Laboratory values
^*eGFR, ml/min/1.73m²	54.1 (41.6–70.5)	58 (46–75)	53 (40–70)	0.114
eGFR< 45 ml/min/1.73m², n (%)	125 (30)	24 (25)	104 (33)	0.137
^†uACR, mg/g	22.1 (11.5–65.4)	23.9 (12.4–68.1)	21.2 (12.4–64.5)	0.473
^‡Calcium, mg/dL	9.44 (9.1–9.9)	9.40 (9.08–9.80)	9.48 (9.12–9.96)	0.151
^‡Phosphate, mg/dL	2.88 (2.43–3.31)	2.88 (2.45–3.38)	2.85 (2.42–3.31)	0.917
Bicarbonate, mEq/L	22.8 (21.2–25.0)	22.6 (21.3–23.8)	23.0 (21.2–25.4)	0.185
^¶Albumin, g/dL	4.4 (4.2–4.6)	4.5 (4.4–4.7)	4.4 (4.2–4.6)	0.004
Outcome
Graft failure within 5 years, n (%)	16 (4)	6 (6)	10 (3)	0.173
Time to graft failure, years	3.51 (2.87–4.19)	3.14 (2.86–3.94)	3.62 (3.02–4.14)	0.588

Continuous data are presented as median (interquartile range) and categorical as number (percentage).
^P-values calculated by Mann-Whitney test for continuous data and Chi-squared test for categorical data, comparing living with deceased donor recipients. A p-value of < 0.05 was considered statistically significant.
^*eGFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation
^†urine albumin:creatinine ratios were acquired by converting urine protein:creatinine ratios using an online calculator [5] and thereafter switching units from mg/mmol to mg/g by multiplying values by 8.84
^‡Calcium and phosphate were measured in mmol/L and converted to mg/dL by multiplying values by 4 and 3.1 respectively
^¶Albumin was measured in g/L and converted to g/dL by dividing by 10
Abbreviations: ADPKD (autosomal dominant polycystic kidney disease), eGFR (estimated glomerular filtration rate)

ISSN: 1471-2369