Survival in chronic dialysis in Argentina: period 2004-2008

Abstract

We show the Kaplan-Meier (KM) survival of inident patients (01/04/2004 to 31/12/2008) to the Argentine Registry of Chronic Dialysis (CD). Follow up (N = 27 224) had a maximum of 2101 days or 69.07 months, in this period 9747 patients died and 10,319 patients stayed alive to 31/12/2009. The median survival was 47.9 months. The multivariate Cox proportional hazards model was used to determine relative risk (RR) or Hazard Ratio (HR) between each independent variable to CD incident patients. Of all the variables we analize 29 (provided they do not conflict with each other and missing cases were <25%), 19 are shown as significant predictor variables: age at admission (4.1% increased risk of death per year), the presence of: heart failure, persistent angor or previous myocardial infarction, cerebrovascular disease, peripheral vascular insufficiency, Hepatitis C virus +, cardiac arrhythmia, have received transfusions in the past 6 months, chronic lung disease, neoplasia and be a carrier of AIDS. So is diabetic nephropathy as a cause of chronic renal disease, but when adjusted for the other variables decreased from 51% (in the univariate) to 37% in the multivariate analysis. The social variables such as no incomes, substandard housing and the absence of previous nephrologic care, as lack of anti Hepatitis B virus vaccination are significant for poor prognosis. Beginning CD with a higher clearance (estimated by MDRD) is a poor prognostic sign, for each mI / min increase in the initial screening, increases the risk of death 0.1%, significantly. The only 2 significant favorable predictors proved to be the presence of hypertension at baseline and be a resident of Capital Federal. Finally we evaluated only the population starting treatment in hemodialysis (HD). It represents 97.5% of the total (26547/27224) of 2004-2008 incident patients, including temporary (non-tunneled catheter) access in multivariate Cox model for this patients. Appeared with great impact on survival: starting HD with transient access, with a RR of death at 1 year of 2.04 (104% higher). Conclusions: we identified some variables at the beginning of dialysis related with survival to year, some of them have already been identified by numerous other authors (such as comorbid factors, albumin, etc), others are related to socioeconomic factors, MDRD calculated filtrate and transitory catheter in degree of significance that are inputs to future confirmations from this study.