Clinical outcomes of elderly patients undergoing chronic peritoneal dialysis: experiences from one center and a review of the literature

Abstract

The purpose of this study was to evaluate the outcome and to identify predictors of mortality in elderly patients on chronic peritoneal dialysis (CPD). We retrospectively reviewed the charts of patients who started on CPD at the Division of Nephrology, University Health Network (UHN), Toronto, from 1 January 1994 to 31 December 2001. Patients were divided into three different age groups (</=64 years, 65-74 years, and >/=75 years). Baseline variables included demographics, information on primary kidney disease, comorbidities when dialysis was first started, and initial biochemical data such as serum albumin, serum calcium (corrected for protein), phosphate, hemoglobin (Hb), total cholesterol, and triglyceride. The effects of these variables on survival were studied using a univariate procedure and then analyzed using multivariate Cox proportional hazards models in order to evaluate their independent relation to mortality. This study included 358 patients, among whom 213 (59.5%) were </=64 years old; 88 (24.6%) were 65-74, and 57 (15.9%) were >/=75 years old. Mean actuarial (death-censored) technique survival for the overall study population was 72.4 months (95% confidence interval [CI]: 66.3-78.5); in the </=64, 65-74, and >/=75 year-old groups mean survivals were 74.4, 62.0, and 64.5 months, respectively. The death-censored technique survival for the elderly patients was not statistically significantly different from that in young patients (P = 0.778). In the overall study population, the mean patient survival was 70.4 months (95% CI 64.2-76.6), while the mean survivals for the </=64, 65-74, and >/=75 year-old groups were 82.3, 54.0, and 50.0 months, respectively. The overall survival rates at 12 months were 98%, 84%, and 85% for the </=64, 65-74, and >/=75 year-old groups, respectively. Not surprisingly, the survival of elderly patients on CPD is shorter than that of younger patients (P = 0.000). There were no significant differences between the two elderly groups (P = 0.439). Mortality was predicted by lower initial serum total cholesterol and albumin as well as higher serum calcium levels. Our study shows that elderly patients starting CPD had a death-censored technique survival comparable to that of younger patients. As expected, the survival of elderly patients on CPD was shorter than the survival of younger patients. Lower initial serum total cholesterol and albumin as well as higher initial serum calcium were associated with mortality in the elderly population. Our findings indicate that chronic peritoneal dialysis is a successful dialysis option for elderly patients with end stage renal disease. Measures to improve their nutritional state and achieve normalization of serum calcium might improve their survival.