Kidney failure from kidney stones: an ANZDATA study

Abstract

ABSTRACT Background Kidney stones are common, with an increasing trend over time, and have been well studied in the general population. However, the incidence and outcomes of kidney stones leading to kidney failure (KF) and the receipt of kidney replacement therapy (KRT) are poorly examined. We examined the incidence of KF due to kidney stones and compared outcomes with KRT patients due to other causes. Methods We studied adult patients who started KRT (January 1981–December 2020) and are included in the Australia and New Zealand Dialysis and Transplant (ANZDATA) registry. Exposure was KRT patients due to kidney stones, comparing them with patients with other causes. We examined incidence, prevalence, patient survival (KRT and transplant) and graft survival (transplant). Cox regression models were fitted to compare patient survival between the 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. The incidence was 1.17 per million population per year and remained stable during the study period (annual change −0.3% [95% confidence interval (CI) −1.5–0.9]. Survival was higher in kidney stone patients receiving dialysis compared with 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 stones compared with non-kidney stone patients (2.5 versus 1.7 years; P = .001). There was no difference in mortality [HR 1.02 (95% CI 0.82–1.28)] or graft loss [HR 1.07 (95% CI 0.79–1.45)] between the kidney stones and non-kidney stones patients in the kidney transplant group. Conclusion The incidence of KF due to kidney stones was unchanged over the study period. Survival of patients with kidney stones who require KRT was better compared with patients with other causes. For the kidney transplant group, survival and risk of graft failure were similar.