Survival of propensity matched incident peritoneal and hemodialysis patients in a United States health care system

We sought to compare survival among incident peritoneal dialysis (PD) patients to matched hemodialysis (HD) patients who received pre-dialysis care, including permanent dialysis access placement. Patients starting PD were propensity matched to those starting HD. HD patients who used a central venous catheter during the first 90 days of dialysis were excluded. Stratified Cox proportional hazards models were used to compare patient survival using both intent-to-treat and as-treated analyses. In the intent-to-treat analysis, patients were followed from the date of first dialysis until death and censored at the earliest of the following: renal transplantation, death, renal recovery, loss to follow-up or study end. In the as-treated analysis, patients were also censored at the time of modality change. A total of 1003 matched pairs were obtained from 11,301 incident patients (10,298 HD and 1003 PD). The cumulative hazard ratio for death at one year was 2.38 (95% CI 1.68-3.40) and 2.10 (1.50-2.94) for HD relative to PD patients in the as-treated and intent-to-treat analyses, respectively. The cumulative risk of death, as estimated by the cumulative hazard ratio, favored PD for almost up to 3 years of follow-up in the as-treated analysis and nearly 2 years of follow-up in the intent-to-treat analysis with no differences thereafter. The higher adjusted rate of death observed for HD patients cannot be attributed to initial use of central venous catheters or lack of pre-dialysis care.