Risk factors for dialysis withdrawal: An analysis of the Australia and New Zealand dialysis and transplant (ANZDATA) registry, 1999-2008

Background and objectives Dialysis withdrawal (DW) in patients with ESRD is increasing in importance. This study assessed causes of death and risk factors for DW in Australia and New Zealand in the first year of dialysis. Design, setting, participants, & measurements This retrospective observational cohort study included all adult Australians and New Zealanders beginning renal replacement therapy in 1999-2008. Results A total of 24,884 patients with 10,073 deaths were included. Deaths from cardiac and social causes (predominantly DW) accounted for 38% and 28% of all deaths, respectively. Cumulative incidence of DW was 3.5% at 1 year (95% confidence interval [CI], 3.3%-3.8%), 9.0% at 3 years (95% CI, 8.6%-9.4%), and 13.4% at 5 years (95% CI, 12.8%-13.9%). In multivariate analysis, predictors for DW in the first year were older age (subhazard ratio [SHR], 1.70 per decade [95% CI, 1.59-1.83]; P<0.001), late referral (SHR, 1.83 [95% CI, 1.59-2.11]; P<0.001), comorbid conditions (SHR, 1.33 per each additional comorbid condition [95% CI, 1.25-1.41]; P<0.001), and diabetes (SHR, 1.16 [95% CI, 1.00-1.34]; P=0.05). Negative predictors for DW included male sex (SHR, 0.75 [95% CI, 0.66-0.87]; P<0.001), indigenous ethnicity (SHR, 0.74 [95% CI, 0.58-0.95]; P=0.02), other nonwhite race (SHR, 0.66 [95% CI, 0.48-0.91]; P=0.01), and peritoneal dialysis user (SHR, 0.59 [95% CI, 0.49-0.72]; P<0.001). Conclusions DW is common among dialysis patients in Australia and New Zealand. Risk factors include older age, female sex, white race, diabetes, higher comorbidity burden, hemodialysis user, and late referral to nephrologist.