title: Survival in patients treated by long-term dialysis compared with the general population.
abstract: BACKGROUND
  Relative survival, a methodology previously used in epidemiologic studies of cancer, compares the observed survival of a patient cohort with expected survival derived from general population life tables. We examined relative survival in patients treated by long-term dialysis in the Italian Dialysis and Transplantation Registry in order to determine the prognosis of dialysis patients.
  
  
  METHODS
  Cohort study drawn from a registry.
  
  
  METHODS
  Patients enrolled in the Italian Dialysis and Transplantation Registry.
  
  
  METHODS
  Sex, age, primary kidney disease, renal replacement therapy modality, and main comorbid conditions.
  
  
  RESULTS
  Death from any cause.
  
  
  METHODS
  Relative survival ratio (the ratio of observed survival in the population of interest to the survival expected given the age- and period-specific mortality of the general population) and excess mortality rate (difference between observed and expected mortality rates).
  
  
  RESULTS
  In January 2000 to December 2008, a total of 27,642 patients were included. The 5-year relative survival estimate was 55.6% (95% CI, 54.7%-56.5%). The excess mortality rate showed a peak at 3 months (21 deaths/100 patient-years), then decreased, becoming constant from the end of year 1 to year 8, with leveling off at about 10 deaths/100 patient-years. Older age, systemic diseases, and diabetes showed the strongest association with excess mortality. Peritoneal dialysis was associated with a lower relative excess risk in only the first year of treatment.
  
  
  CONCLUSIONS
  The patient cohort comprises about half the Italian patients beginning dialysis therapy in the period.
  
  
  CONCLUSIONS
  This study highlights the applicability of relative survival methods in dialysis patients. This measure allows estimation of disease prognosis and severity comparisons among chronic diseases. The excess mortality rate appears to be a more sensitive and informative measure than the simple proportion of survivors.
authors.affiliation: Nephrology and Dialysis Unit, ULSS 15, Camposampiero-Cittadella, Padua, Italy. maurizio.nordio@gmail.com
authors.forename: Maurizio
authors.initials: M
authors.lastname: Nordio
authors.forename: Aurelio
authors.initials: A
authors.lastname: Limido
authors.forename: Umberto
authors.initials: U
authors.lastname: Maggiore
authors.forename: Michele
authors.initials: M
authors.lastname: Nichelatti
authors.forename: Maurizio
authors.initials: M
authors.lastname: Postorino
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Quintaliani
mesh_terms: D000328:Adult; D000368:Aged; D002423:Cause of Death; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007558:Italy; D007676:Kidney Failure, Chronic / Q000175:diagnosis / Q000401:mortality* / Q000628:therapy*; D008134:Long-Term Care; D008297:Male; D008875:Middle Aged; D009026:Mortality / Q000639:trends*; D011379:Prognosis; D012042:Registries; D006435:Renal Dialysis / Q000379:methods / Q000401:mortality*; D012189:Retrospective Studies; D018570:Risk Assessment; D016019:Survival Analysis; D013997:Time Factors; D055815:Young Adult