**2. Mortality on PD and HD**

Although in 2005 the European Best Practice Guidelines for Peritoneal Dialysis conclude, on the basis of the available data, that peritoneal dialysis is a good treatment prior to renal transplantation there are contradictory survival rates reported in the literature for patients either on HD or on PD[6].

In 1995, data from the US Renal Data Systems from more than 170,000 patients showed, thatprevalent patients treated with PD had a 19% higher adjusted mortality risk (p< 0.001) than those treated with HD [7].

In a comparable analysis obtained from the Canadian Organ Replacement Register, using data from 11,970 ESRD patientswho initiated treatment between 1990 and 1994 and were followedup for a maximum of 5 years was themortality rate ratio for CAPD/CCPD relative to hemo‐ dialysis, as estimated by Poisson regression, was 0.73. There, the increased mortality on hemodialysis compared with CAPD/CCPD was concentrated in the first 2 years of follow-up and was detectable in all subgroups defined by age and diabetes status [8].

In contrast, a study comparing two year mortality rates of patients on the waiting list for renal transplantation to a historical prospective cohort of more than 12000 PD and HD patients disclosed, that especially for patients with a body mass index (BMI) of>= 26 mortality was increased with PD as dialysis modality [9].

Nevertheless, in a cohort of more than 3000 non-diabetic patients starting dialysis there was no difference in survival for patients treated either with PD or HD [10].

Also, in the well-known, prospective Netherlands Cooperative Study on the Adequacy of Dialysis (NECOSAD) adjusted mortality rates between HD and PD patients were similar for the first two years. Thereafter, an increase in mortality especially in patients >= 60 years was detected [11].

Comparable results were seen in a prospective multicenter cohort study in 1041 patients (767 HD, 274 PD). There, the risk of mortality was equal in both groups for the first year with an increase in the second year. In addition, 25% of PD but only 5% of the HD patients switched their type of dialysis modality [12].
