title: How should we analyze and present mortality in our patients?: A multicentre GCDP experience.
abstract: BACKGROUND
  There are different strategies to analyse mortality in peritoneal dialysis (PD) with different definitions for case, event, time at risk, and statistical tests. A common method for the different registries would enable proper comparison to better understand the actual differences in mortality of our patients.
  
  
  METHODS
  We review and describe the analysis strategies of regional, national and international registries. We include actuarial survival, Kaplan-Meier (KM) and competitive risk (CR) analyses. We apply different approaches to the same database (GCDP), which show apparent differences with each method.
  
  
  RESULTS
  A total of 1,890 incident patients in PD from 2003-2013 were included (55 years; men 64.2%), with initial RRF of 7ml/min; 25% had diabetes and a Charlson index of 3 [2-4]; 261 patients died, 380 changed to haemodialysis (HD) and 682 received a transplant. Annual mortality rates varied up to 20% in relative numbers (6.4 vs. 5.2%) depending on the system applied. The estimated probability of mortality measured by CR progressively differs from the KM over the years: 3.6 vs. 4.0% the first year, then 9.0 vs. 11.9%, 15.6 vs. 28.3%, and 18.5 vs. 43.3% the following years.
  
  
  CONCLUSIONS
  Although each method may be correct in themselves and express different approaches, the final impression left on the reader is a number that under/overestimates mortality. The CR model better expresses the reality of PD, where the number of patients lost to follow-up (transplant, transfer to HD) it is 4 times more than deceased patients and only a quarter remain on PD at the end of follow up.
authors: Servicio de Nefrología, Hospital Universitario Puerta de Hierro-Majadahonda, Majadahonda (Madrid), España. Electronic address: dxaneiro@hotmail.com.
authors: Darío
authors: D
authors: Janeiro
authors: Servicio de Nefrología, Hospital Universitario Puerta de Hierro-Majadahonda, Majadahonda (Madrid), España.
authors: José
authors: J
authors: Portolés
authors: Servicio de Nefrología, Hospital Universitario Puerta de Hierro-Majadahonda, Majadahonda (Madrid), España.
authors: Paula
authors: P
authors: Lopez-Sanchez
authors: Servicio de Nefrología, Hospital Universitario Clínico San Carlos, Madrid, España.
authors: Fernando
authors: F
authors: Tornero
authors: Servicio de Nefrología, Hospital Nuestra Señora de Sonsoles, Ávila, España.
authors: Carmen
authors: C
authors: Felipe
authors: Servicio de Nefrología, Hospital San Pedro de Alcántara, Cáceres, España.
authors: Inés
authors: I
authors: Castellano
authors: Servicio de Nefrología, Hospital Ramón y Cajal, Madrid, España.
authors: Maite
authors: M
authors: Rivera
authors: Servicio de Nefrología, Hospital Universitario Puerta de Hierro-Majadahonda, Majadahonda (Madrid), España.
authors: Jeanette
authors: J
authors: Fernandez-Cusicanqui
authors: Servicio de Nefrología, Hospital Universitario Infanta Sofía, Madrid, España.
authors: Antonio
authors: A
authors: Cirugeda
authors: Servicio de Nefrología, Hospital General de Segovia, Segovia, España.
authors: María José
authors: MJ
authors: Fernandez-Reyes
authors: Servicio de Nefrología, Hospital Universitario de Guadalajara, Guadalajara, España.
authors: José Ramón
authors: JR
authors: Rodriguez-Palomares
authors: Servicio de Nefrología, Hospital Universitario La Paz, Madrid, España.
authors: María Auxiliadora
authors: MA
authors: Bajo
authors: Servicio de Nefrología, Hospital General de Ciudad Real, Ciudad Real, España.
authors: Guadalupe
authors: G
authors: Caparrós
authors: Servicio de Nefrología, Fundación Jiménez Díaz, Madrid, España.
authors: Alberto
authors: A
authors: Ortiz
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D010530:Peritoneal Dialysis / Q000401:mortality*; D012042:Registries; D006435:Renal Dialysis; D012189:Retrospective Studies; D012307:Risk Factors
keywords: Diálisis peritoneal; Mortalidad; Mortality; Peritoneal dialysis; Supervivencia; Survival