Icodextrin use for peritoneal dialysis in Australia: A cohort study using Australia and New Zealand Dialysis and Transplant Registry

BACKGROUND

Icodextrin is a high molecular weight, starch-derived glucose polymer that is used as an osmotic agent in peritoneal dialysis (PD) to promote ultrafiltration. There has been wide variation in its use across Australia and the rest of the world, but it is unclear whether these differences are due to patient- or centre-related factors.

METHODS

Using the Australia and New Zealand Dialysis and Transplant Registry, all adult patients (>18 years) who started PD in Australia between 1 January 2007 and 31 December 2014 were included. The primary outcome was icodextrin use at PD commencement. Hierarchical logistic regression clustered around the treatment centre was applied to determine the patient- and centre-related characteristics associated with icodextrin use. The impact of centre-level practice pattern variability on icodextrin uptake was estimated using the intra-cluster correlation coefficient (ICC).

RESULTS

Of 5948 patients starting on PD in 58 centres during the study period, 2002 (33.7%) received icodextrin from the outset. Overall uptake of icodextrin increased from 29% in 2010 to 42.5% in 2014. Patient-level characteristics associated with an increased likelihood of commencing PD with icodextrin included male sex (adjusted odds ratio (OR) 1.55, 95% confidence interval (CI) 1.35-1.77; p < 0.001), prior haemodialysis or kidney transplantation (OR 1.26, 95% CI 1.09-1.47), obesity (OR 1.66, 95% CI 1.41-1.96), diabetes mellitus (OR 2.32, 95% CI 2.03-2.64) and residing in a postcode with the highest decile of socio-economic status (OR 1.43, 95% CI 1.11-1.85). The centre-level characteristic associated with an increased likelihood of commencing PD with icodextrin was routine assessment of a peritoneal equilibration test (OR 1.45, 95% CI 1.27-1.66). Centres with fewer patients on automated peritoneal dialysis (APD) were less likely to start on icodextrin (APD proportion <57%; OR 0.45, 95% CI 0.20-0.99). Centre factors accounted for 25% of the variation in icodextrin use solution among incident PD patients (ICC 0.25).

CONCLUSIONS

Icodextrin use in incident Australian PD patients is increasing variable and associated with both patient and centre characteristics. Centre-related factors explained 25% of variability in icodextrin use.

The Effect of Automated versus Continuous Ambulatory Peritoneal Dialysis on Mortality Risk in China

Background

There is an emerging practice pattern of automated peritoneal dialysis (APD) in China. We report on outcomes compared to continuous ambulatory peritoneal dialysis (CAPD) in a Chinese cohort.

Methods

Data were sourced from the Baxter Healthcare (China) Investment Co. Ltd Patient Support Program database, comprising an inception cohort commencing PD between 1 January 2005 and 13 August 2015. We used time-dependent cause-specific Cox proportional hazards and Fine-Gray competing risks (kidney transplantation, change to hemodialysis) models to estimate relative mortality risk between APD and CAPD. We adjusted or matched for age, gender, employment, insurance, primary renal disease, size of PD program, and year of dialysis inception. We used cluster robust regression to account for center effect.

Results

We modeled 100,351 subjects from 1,178 centers over 240,803 patient-years. Of these, 368 received APD at some time. Compared with patients on CAPD, those on APD were significantly younger, more likely to be male, employed, self-paying, and from larger programs. Overall, APD was associated with a hazard ratio (HR) for death of 0.79 (95% confidence interval [CI] 0.64 – 0.97) compared with CAPD in Cox proportional hazards models, and 0.76 (0.62 – 0.95) in Fine-Gray competing risks regression models. There was prominent effect modification by follow-up time: benefit was observed only up to 4 years follow-up, after which risk of death was similar.

Conclusion

Automated peritoneal dialysis is associated with an overall lower adjusted risk of death compared with CAPD in China. Analyses are limited by the likelihood of important selection bias arising from group imbalance, and residual confounding from unavailability of important clinical covariates such as comorbidity and Kt/V.