Use of a new end-stage kidney disease risk calculator in the Kidney Disease Improving Global Outcomes guideline to evaluate the impact of different living kidney donor candidate assessments.

AIM: The Kidney Disease Improving Global Outcomes (KDIGO) guideline recommends the incorporation of a new risk calculator that quantifies the end-stage kidney disease (ESKD) risk based on a composite profile of risk factors in living kidney donor candidates (LKDC). We compared the ESKD risk estimates in previously declined versus accepted LKDC to evaluate the predictive capacity and potential impact of this tool.
METHODS: Baseline 15 year and lifetime ESKD risk estimates without donation were calculated using the risk calculator for LKDC assessed from two centres between 2007 and 2015. LKDC suitability based on the proposed KDIGO and the existing Caring for Australasians with Renal Impairment national guidelines was compared.
RESULTS: Median 15 year ESKD risk was 0.14% (IQR 0.09-0.31%) in declined LKDC (n=59) versus 0.10% (0.07-0.14%) in accepted LKDC (n=89) (P<0.001). Lifetime risk was similar: 0.39% (0.23-0.80%) versus 0.35% (0.22-0.56%), respectively; however, declined LKDC had a higher 98% risk percentile value (8.19% vs 1.02%) and were more likely to exceed a 1% ESKD risk threshold (15% vs 1%; P<0.01). The calculator captured reasons for declining donation in only 39% of LKDC; 46.9% of LKDC with Caring for Australasians with Renal Impairment contraindications were reclassified as having an acceptable (≤1%) lifetime risk and no KDIGO contraindications, primarily related to a lower pre-donation glomerular filtration rate or controlled hypertension with obesity.
CONCLUSION: Declined LKDC had a higher 15 year but similar lifetime ESKD risk. However, the calculator successfully differentiated declined LKDC with a lifetime risk >1%. This risk calculator appears to complement but not replace clinical evaluation.