Trend and determinants of mortality in incident hemodialysis patients of the Lazio region

Background. In the last decades some studies observed a moderate progressive decrease in short-term mortality in incident hemodialysis patients. The aim of the study is to analyse the mortality trends in patients starting hemodialysis using the Lazio Regional Dialysis and Transplant Registry.Methods. Patients who started chronic hemodialysis between 2008 and 2016 were included. Annual 1-year and 3-year Crude Mortality Rate*100 Person Years (CMR*100PY) overall, by gender and age classes were calculated. Cumulative survival estimates at 1 year and 3 years since the date of starting hemodialysis were presented as Kaplan-Meier curves for the three periods and compared using the log-rank test. The association between periods of incidence in hemodialysis and 1-year and 3-year mortality were investigated by means of unadjusted and adjusted Cox regression models. Potential determinants of both mortality outcomes were also investigated.Results. Among 6,997 hemodialysis patients (64.5% males, 66.1% over 65 years old) 923 died within 1 year and 2,253 within 3 years form incidence; CMR*100PY were 14.1 (95%CI: 13.2-15.0) and 13.7 (95%CI: 13.2-14.3), respectively; both remained unchanged over the years. Even after stratification by gender and age classes no significant changes emerged. Kaplan-Meier mortality curves did not show any statistically significant differences in survival at 1 year and 3 years from hemodialysis incidence across periods. No statistically significant associations were found between periods and 1-year and 3-year mortality. Factors associated with a greater increase in mortality are: being over 65 years, born in Italy, not being self-sufficient, having systemic versus undetermined nephropathy, having heart disease, peripheral vascular disease, cancer, liver disease, dementia and psychiatric illness, and receiving dialysis by catheter rather than fistula.Conclusions. The study shows that the mortality rate in patients with end-stage renal disease starting hemodialysis in the Lazio region was stable over 9 years.