Associations between diabetes and sex with peritoneal dialysis technique and patient survival: Results from the Australia and New Zealand Dialysis and Transplant Registry cohort study.

BACKGROUND: A differential association between mortality and cause of end-stage kidney disease in patients with type 2 diabetes mellitus (T2DM) has been shown. Sex-specific differences in diabetes-related complications have been described. It is unclear whether sex affects the associations between diabetes and peritoneal dialysis (PD) technique and patient survival. METHODS: Using the Australia and New Zealand Dialysis and Transplant Registry, we examined a two-way interaction between sex and diabetes status (no diabetes, T2DM and non-diabetic nephropathy [T2DM + non-DN] and T2DM and diabetic nephropathy [T2DM + DN]) for PD technique failure (including death), all-cause mortality and cause-specific mortality in incident adult PD patients between 1996 and 2016 using adjusted Cox regression. Mediation analysis was conducted to determine whether peritonitis was a mediator in these associations. RESULTS: In 8279 PD patients, those with T2DM + DN had the greatest risks in technique failure, all-cause mortality and cause-specific mortality followed by patients with T2DM + non-DN, then patients without diabetes. Sex modified the association with diabetes status in technique failure (pinteraction = 0.001) and cardiac mortality (pinteraction = 0.008). In women with T2DM + DN, the adjusted hazard ratio (HR) for technique failure was 1.45 (1.30-1.62) and was higher than men with T2DM + DN (1.17 [1.08-1.28]; referent: no diabetes). In women with T2DM + DN, the adjusted HR for cardiac mortality was 2.12 (1.73-2.61) and was also higher than men with T2DM + DN (1.66 [1.43-1.95]). Less than 10 % of the effect between diabetes and PD technique failure or mortality was mediated by peritonitis. CONCLUSIONS: PD patients with diabetic nephropathy had increased risk of PD technique failure and mortality, with the magnitude of these risks greater in women.

Incidence and factors associated with geographical relocation in patients receiving renal replacement therapy.

BACKGROUND: Renal replacement therapy (RRT) places a burden on patients, and geographical relocation for easier access to healthcare facilities is a necessity for some. Incidence and factors associated with relocation has not been comprehensively examined at a national level. We aimed to determine proportion, incidence, characteristics of RRT patients who relocate and relocation rate by remoteness of residence and dialysis modality. METHODS: Retrospective cohort analysis using Australian and New Zealand Dialysis and Transplant Registry to examine RRT patients in Australia from January 2005 to December 2015. Relocation incidence was calculated for remoteness of residence and RRT modality as rate per 100 patient years. Factors associated with relocation were examined using competing risk regression models with death as a competing event. RESULTS: Of 24,676 incident patients on RRT, 5888 (23.9%) relocated with a median time of 1.6 years [IQR 0.7-3.4] years. Relocation incidence was 7.9 per 100 patient years and increased from major cities to very remote regions (7.2 to 48.8 per 100 patient years respectively, p < 0.001). Remoteness of residence was associated with geographical relocation in competing risk analysis especially in remote (SHR 1.20, 95%CI 1.01, 1.41 p = 0.034) and very remote regions (SHR 3.51 95% 3.05, 4.04 p < 0.001). Aboriginal or Torres Strait Islander ethnicity, compared to Caucasian, was independently associated with relocation (SHR 1.18, 95% CI 1.06,1.31, p = 0.002) while transplant patients were less likely to relocate compared to haemodialysis patients (HR 0.37, 95%CI 0.34, 0.39, p < 0.001). CONCLUSIONS: Relocation in patients receiving RRT is associated with remoteness of residence, RRT modality and ethnicity. Reasons for relocation and its impact on patient wellbeing and outcome should be further explored.

Multicentre registry data analysis comparing outcomes of culture-negative peritonitis and different subtypes of culture-positive peritonitis in peritoneal dialysis patients.

BACKGROUND: The outcomes of culture-negative peritonitis in peritoneal dialysis (PD) patients have been reported to be superior to those of culture-positive peritonitis. The current study aimed to examine whether this observation also applied to different subtypes of culture-positive peritonitis. METHODS: This multicentre registry study included all episodes of peritonitis in adult PD patients in Australia between 2004 and 2014. The primary outcome was medical cure. Secondary outcomes were catheter removal, hemodialysis transfer, relapsing/recurrent peritonitis and peritonitis-related death. These outcomes were analyzed using mixed effects logistic regression. RESULTS: Overall, 11,122 episodes of peritonitis occurring in 5367 patients were included. A total of 1760 (16%) episodes were culture-negative, of which 77% were medically cured. Compared with culture-negative peritonitis, the odds of medical cure were lower in peritonitis caused by Staphylococcus aureus (adjusted odds ratio (OR) 0.62, 95% confidence interval (CI) 0.52-0.73), Pseudomonas species (OR 0.20, 95% CI 0.16-0.26), other gram-negative organisms (OR 0.48, 95% CI 0.41-0.56), polymicrobial organisms (OR 0.30, 95% CI 0.25-0.35), fungi (OR 0.02, 95% CI 0.01-0.03), and other organisms (OR 0.61, 95% CI 0.49-0.76), while the odds were similar in other (non-staphylococcal) gram-positive organisms (OR 1.11, 95% CI 0.97-1.28). Similar results were observed for catheter removal and hemodialysis transfer. Compared with culture-negative peritonitis, peritonitis-related mortality was significantly higher in culture-positive peritonitis except that due to other gram-positive organisms. There was no difference in the odds of relapsing/recurrent peritonitis between culture-negative and culture-positive peritonitis. CONCLUSION: Culture-negative peritonitis had superior outcomes compared to culture-positive peritonitis except for non-staphylococcal gram-positive peritonitis.