Kidney Failure from Kidney Stones: An ANZDATA Registry Study.

ABSTRACT

INTRODUCTION: Kidney stones is common with an increasing trend over time and has been well studied in the general population. However, incidence and outcomes of kidney stones leading to kidney failure (KF) and receiving kidney replacement therapy (KRT) is poorly examined. We examined the incidence of KF due to kidney stones and compared outcomes to KRT patients due to other causes. METHODS: Adult patients who started KRT (January 1981-December 2020) and based in the Australia and New Zealand Dialysis and Transplant (ANZDATA) registry. Exposure was KRT patients due to kidney stones comparing them to those with other causes. We examined incidence, prevalence, patient survival (KRT and transplant) and graft survival (transplant). Cox regression models were fit to compare patient survival between kidney stones and non-kidney stones groups, overall KRT, dialysis and patient and graft survival after kidney transplant. RESULTS: A total of 834 (1.1%) patients commenced KRT due to kidney stones. Incidence was 1.17 per million population per year and remained stable during the study period (annual percentage change -0.3% [95%CI -1.5% to 0.9%]. Survival was higher in kidney stone patients receiving dialysis compared to the non-kidney stone group (hazard ratio [HR], 0.89, 95%CI 0.82- 0.96) with similar estimates in a matched cohort. In kidney transplant patients, time to transplant was longer for patients with kidney stone compared to non-kidney stone patients (2.5 vs 1.7 years, P=0.001). There was no mortality difference (HR 1.02, 95%CI 0.82- 1.28) or graft loss (HR 1.07, 95%CI 0.79- 1.45) between kidney stones vs non-kidney stones in the kidney transplant group. CONCLUSION: KF due to kidney stones incidence is unchanged over the study period. Survival of patients with kidney stones who require KRT was better compared to patients from other causes. For the kidney transplant group, survival and risk of graft failure were similar.