Recent reports indicate a decreased mortality risk for patients on chronic peritoneal dialysis in the United States. We sought to determine whether a higher use of automated versus continuous ambulatory peritoneal dialysis was associated with this improvement. Analyses were carried out using data from the United States Renal Data System on 66,381 incident patients on chronic peritoneal dialysis in the years 1996-2004 that were adjusted for demographic, clinical, laboratory and dialysis facility characteristics. Patients were followed until the time of transfer to other modes of dialysis, transplant, or death, whichever occurred first, or until their last follow-up through September 2006. Over time, the risks were substantially reduced such that the adjusted hazard ratios for death or technique failure of these patients in the 2002-2004 period were 0.55 (0.53, 0.57) and 0.62 (0.59, 0.64), respectively, compared with those of incident patients during the years 1996-1998. The risk improvements for both modes of dialysis were, however, found to be similar. Under intent-to-treat, time-dependent, and as-treated analysis, there was little or no difference in risk for death or in technique failure. Thus, the improved chronic peritoneal dialysis outcomes cannot be attributed to a greater use of automated peritoneal dialysis.

Purpose of review

There have been differential changes in outcomes of patients treated with in-center hemodialysis and peritoneal dialysis. In light of these changes, providers and practices should reevaluate the utilization of peritoneal dialysis.

Recent findings

Accumulating evidence confirms that the present distribution of dialysis modality in the United States does not reflect patient choice. Furthermore, in most recent cohorts, the 5-year adjusted survival of patients treated with hemodialysis and peritoneal dialysis is remarkably similar (35 and 33% respectively). Similar results have been reported from Canada, Australia, and New Zealand. Moreover, health-related quality of life of peritoneal dialysis patients are no different from that reported by those treated with nocturnal hemodialysis. Finally, an expansion of use of peritoneal dialysis for the treatment of end-stage renal disease makes economic sense for the taxpayers - the payors for dialysis services.

Summary

The improvement in outcomes of peritoneal dialysis patients makes a compelling argument for the expansion of the use of the therapy for the treatment of end-stage renal disease in the United States. We think that 20-40% of patients can be treated with peritoneal dialysis. However, any expansion in use should be done gradually and should include training healthcare providers while continuously monitoring patient outcomes.

Background

The annual payer costs for patients treated with peritoneal dialysis (PD) are lower than with hemodialysis (HD), but in 2007, only 7% of dialysis patients in the United States were treated with PD. Since 1996, there has been no change in the first-year mortality of HD patients, but both short- and long-term outcomes of PD patients have improved.

Methods

Data from the US Renal Data System were examined for secular trends in survival among patients treated with HD and PD on day 90 of end-stage renal disease (HD, 620 020 patients; PD, 64 406 patients) in three 3-year cohorts (1996-1998, 1999-2001, and 2002-2004) for up to 5 years of follow-up using a nonproportional hazards marginal structural model with inverse probability of treatment and censoring weighting.

Results

There was a progressive attenuation in the higher risk for death seen in patients treated with PD in earlier cohorts; for the 2002-2004 cohort, there was no significant difference in the risk of death for HD and PD patients through 5 years of follow-up. The median life expectancy of HD and PD patients was 38.4 and 36.6 months, respectively. Analyses in 8 subgroups based on age (<65 and ≥65 years), diabetic status, and baseline comorbidity (none and ≥1) showed greater improvement in survival among patients treated with PD relative to HD at all follow-up periods.

Conclusion

In the most recent cohorts, patients who began treatment with HD or PD have similar outcomes.

The number of dialysis patients continues to grow. In many parts of the world, peritoneal dialysis (PD) is a less expensive form of treatment. However, it has been questioned whether patients treated with PD can have as good a long-term outcome as that achieved with hemodialysis (HD). This skepticism has fueled ongoing comparisons of outcomes of patients treated with in-center HD and PD using data from national registries or prospective cohort studies. There are major challenges in comparing outcomes with two therapies when the treatment assignment is nonrandom. Furthermore, many of the intermodality comparisons include patients who started dialysis therapy in the 1990s. In many parts of the world, improvements in PD outcome have outpaced those seen with in-center HD. It is not surprising, then, that virtually all the recent observational studies from different parts of the world consistently show that long-term survival of HD and PD patients is remarkably similar. These studies support the case for a greater use of PD for the treatment of end-stage renal disease. This, in turn, could allow more patients to be treated for any given budgetary allocation to long-term dialysis.