Competing risks of death and kidney failure in a cohort of Australian adults with severe chronic kidney disease

Abstract

Objectives To examine the competing risks of death (any cause) and of kidney failure in a cohort of Australian adults with severe chronic kidney disease. Design Population‐based cohort study; analysis of linked data from the Tasmanian Chronic Kidney Disease study (CKD.TASlink), 1 January 2004 – 31 December 2017. Participants All adults in Tasmania with incident stage 4 chronic kidney disease (estimated glomerular filtration rate [eGFR], 15‒29 mL/min/1.73 m2). Main outcome measures Death or kidney failure (defined as eGFR below 10 mL/min/1.73 m2 or initiation of dialysis or kidney transplantation) within five years of diagnosis of stage 4 chronic kidney disease. Results We included data for 6825 adults with incident stage 4 chronic kidney disease (mean age, 79.3 years; SD, 11.1 years), including 3816 women (55.9%). The risk of death increased with age — under 65 years: 0.18 (95% CI, 0.15–0.22); 65‒74 years: 0.39 (95% CI, 0.36‒0.42); 75‒84 years, 0.56 (95% CI, 0.54‒0.58); 85 years or older: 0.78 (95% CI, 0.77‒0.80) — while that of kidney failure declined — under 65 years: 0.39 (95% CI, 0.35–0.43); 65‒74 years: 0.12 (95% CI, 0.10‒0.14); 75‒84 years: 0.05 (95% CI, 0.04‒0.06); 85 years or older: 0.01 (95% CI, 0.01‒0.02). The risk of kidney failure was greater for people with macroalbuminuria and those whose albumin status had not recently been assessed. The risks of kidney failure and death were greater for men than women in all age groups (except similar risks of death for men and women under 65 years of age). Conclusions For older Australians with incident stage 4 chronic kidney disease, the risk of death is higher than that of kidney failure, and the latter risk declines with age. Clinical guidelines should recognise these competing risks and include recommendations about holistic supportive care, not just on preparation for dialysis or transplantation.

The kidney failure risk equation predicts kidney failure: Validation in an Australian cohort

“…Three of these studies 18,23,24 and the large validation study by Tangri et al 6, undertook recalibration for use in an external population 19,25,26 . Previous work has demonstrated differences in practice between Australia and Canada in regards to eGFR and commencement of dialysis 7,8 . To account for this we have analysed several alternative endpoints which have demonstrated similar findings for discrimination to demonstrate the robustness of our results.…”

“… 19 , 25 , 26 Previous work has demonstrated differences in practice between Australia and Canada in regards to eGFR and commencement of dialysis. 7 , 8 To account for this we have analysed several alternative endpoints which have demonstrated similar findings for discrimination to demonstrate the robustness of our results. For calibration, this has demonstrated that the observed and predicted risk are better aligned when using the outcome of <7.5 mL/min/1.73m 2 which further highlight the differences in dialysis initiation practices between systems.…”

“…Typically, the KFRE is used to predict the risk of proceeding to kidney failure requiring KRT. Due to the low utilisation of renal replacement therapy in Tasmania compared to other populations, 7 two alternate endpoints (eGFR <10 and <7.5 mL/min/1.73m 2 ) were implemented to ensure the robustness of results; the methods for these are described in the supplementary appendix. The cut-off of 7.5 mL/min/1.73m 2 was chosen based on the median eGFR start of 7.5 mL/min/1.73m 2 for Australians starting Kidney Replacement Therapy 20 and the cutoff of 10 mL/min/1.73m 2 aligns with the secondary outcome used when originally developing the equation.…”

“…There are differences between the Australian 7 and Canadian cohorts with differences in clinical practice. 8 It is therefore unclear whether we can apply the score in our population without a calibration adjustment factor.…”

Primary and specialist care interaction and referral patterns for individuals with chronic kidney disease: a narrative review

“…Over the years, there has been greater appreciation of the epidemiology of CKD where it has become apparent to clinicians that the major competing risk for dialysis is death from CVD [ 65 , 66 ]. This has resulted in broadening the focus of CKD care to include CVD risk reduction, in addition to or concomitant with, reducing the progressive decline in kidney function.…”