SUN-090 TEMPORAL CHANGES IN CAUSE-SPECIFIC MORTALITY IN THE AUSTRALIAN AND NEW ZEALAND HAEMODIALYSIS POPULATION

Abstract

Haemodialysis patients have a high mortality rate relative to the general population, and cause-specific mortality rates are also different. As the age and comorbid burden of incident dialysis patients has increased, the causes of death on dialysis have changed, and specifically it has been hypothesised that the number of patients withdrawing from haemodialysis for psychosocial reasons has increased. The aims of this study were:To describe the frequency, temporal characteristics and changes in mortality over the last twenty yearsTo identify the predictors of cause-specific mortality in haemodialysis patients over the last twenty years This study included all Australian and New Zealand haemodialysis patients who started dialysis between January 1, 1997 and December 31, 2016, using Australia and New Zealand Dialysis and Transplant Registry data. Competing risk regression models were used to identify predictors of cause-specific mortality, using non-withdrawal cause of death as the competing risk event. Of the 40,447 haemodialysis patients included in this study, the median age was 62 (IQR 50-72) years. There were 61% males and 9% were Aboriginal and Torres Strait Islanders. The median body mass index was 26.8kg/m2. Of the 5,257 deaths between 1997 to 2000, 570 (11%) were secondary to withdrawal. This increased to 549 (32%), from a total of 1,691 deaths, between 2013 to 2016 (p<0.001). Using competing risk regression, covariates which significantly associated with dialysis withdrawal were older age (≥70 years subdistribution hazards ratio (SHR) 1.37, 95% CI 1.29-1.46, p<0.001; reference 60-70 years), recent era (2013-2016 SHR 3.97, 95% CI 3.51-4.49, p<0.001 reference 1997-2000),co-morbid cerebrovascular disease (SHR 1.19, 95% CI 1.17-1.28; p<0.001), chronic lung disease (SHR 1.13, 95% CI 1.06-1.21; p<0.001) and coronary artery disease (SHR 1.18, 95% CI 1.11-1.25; p<0.001). Males (SHR 0.91, 95% CI 0.86-0.96, p<0.001), Subjects of Asian racial origin (SHR 0.66, 95% CI 0.59-0.74, p<0.001; reference Caucasians) were less likely to withdraw from haemodialysis. Withdrawal from haemodialysis was independent of body mass index and aetiology of kidney failure. Withdrawal has emerged as an increasingly common cause of mortality in Australia and New Zealand haemodialysis patients over the last twenty years. Predictors of haemodialysis withdrawal include older age, higher morbidity burden and recent haemodialysis era mortality. The increasing rate of dialysis withdrawal highlights the needs for integrated palliative care services in nephrology.