ESRD patients without co-morbid risk factors at the start of haemodialysisare ideal as survival comparison population

Background. Our aim was to identify co-morbid risk factors in ESRD patients at the start of the treatment, to select patients in the low-risk group (L RG) and to compare overall survival, adjusted overall survival and LRG surv ival in three centres (A, B and C). Methods. Population includes 531 patients entering haemodialysis from 1 Jan uary 1981 to 31 December 1996 (mean age 59.6 +/- 16.7 years). Demographics and co-morbidity data collected at the start of HD were independent variabl es for the analysis. Univariate and multivariate analysis of survival were used to identify significant prognostic factors (Kaplan-Meier and Cox hazar d regression model respectively). According to this analysis the LRG was de fined by the absence of the identified significant mortality risk factors e xcept age. Results. The overall median survival was 7.92 years, with 92.0% survival at 1 year, 65.2% at 5 years and 40.4% at 10 years. The median survival in cen tre C (10.83 years) was significantly higher than median survival in centre A (7.0 years) and in centre B (7.83 years). Centres A and B were afterward s analysed together (A-B). In the multivariate analysis, five variables (st arting age, diabetes, cancer, smoking habit, and arteriosclerotic heart dis ease) were associated with survival. The variable centre (A-B or C) was not significant. The adjusted survival curve for centres A-B and C were not di fferent. The LRG included patients of any age, without diabetes, cancer, sm oking habit, and arteriosclerotic heart disease. The frequency of the patie nts in the LRG was 66.3% in centre C and 45.7% in centre A-B (P=0.0004). Ta king into account only the LRG, the survival comparison between centres A-B and C, did not show significant differences (P= 0.196). Conclusions, We conclude that for purposes of comparison of mortality in ES RD, low-risk population is better than overall ESRD population.