Ten years experience of renal replacement treatment in the elderly

Elderly patients constitute an increasing segment of the end-stage renal disease population beginning renal replacement therapy (RRT) in the Western Countries. In this study we studied 2447 end-stage renal disease (ESRD) patients who started renal replacement treatment (RRT) in Lombardy between 1983 and 1992 at the age of 65 or older, with particular emphasis on survival and morbidity. In the last decade the number of elderly patients admitted yearly to RRT increased from 113 [102 per million population (pmp), 20% of all accepted patients] in 1983 to 375 (282 pmp, 42% of all accepted patients) in 1992. The most frequent primary nephropathies in 1992 were glomerulonephritis (21% vs 25% in 1983), vascular diseases (18% vs 13%) and diabetes (12% vs 7%). The use of acetate HD and IPD declined over the 10 years period from 49 to 11% and from 26 to 5%; that of bicarbonate HD and CAPD increased from 3 to 46% and from 26 to 32%. Hospitalization rate was related to age, sex, presence of systemic nephropathies or malignancy, but not to treatment modality. The main causes of death in 1992 were cardiovascular diseases (53 vs 42% in 1983) and cachexia (24 vs 18%). The survival rate of all elderly patients was 64, 39 and 13% at 2, 4 and 8 years. The covariates affecting patient survival (Cox model) were the presence at the start of RRT of systemic nephropathies (Hazard ratio 1.7), systemic atherosclerosis (1.6), other comorbidity conditions (1.38) and peritoneal dialysis (1.31).

(1) The progressive increase in the number of patients admitted to RRT in the last decade is due to loose criteria of acceptance of elderly patients (increase in the acceptance rate of diabetics and patients with vascular disease), (2) patients' survival is affected by the presence of comorbid conditions at the start of RRT, (3) the worse survival rate in peritoneal dialysis could result from a hidden negative selection of patients, unmeasured by Cox analysis.