title: Automated Peritoneal Dialysis Is Associated with Better Survival Rates Compared to Continuous Ambulatory Peritoneal Dialysis: A Propensity Score Matching Analysis.
abstract: BACKGROUND
  The impact of peritoneal dialysis modality on patient survival and peritonitis rates is not fully understood, and no large-scale randomized clinical trial (RCT) is available. In the absence of a RCT, the use of an advanced matching procedure to reduce selection bias in large cohort studies may be the best approach. The aim of this study is to compare automated peritoneal dialysis (APD) and continuous ambulatory peritoneal dialysis (CAPD) according to peritonitis risk, technique failure and patient survival in a large nation-wide PD cohort.
  
  
  METHODS
  This is a prospective cohort study that included all incident PD patients with at least 90 days of PD recruited in the BRAZPD study. All patients who were treated exclusively with either APD or CAPD were matched for 15 different covariates using a propensity score calculated with the nearest neighbor method. Clinical outcomes analyzed were overall mortality, technique failure and time to first peritonitis. For all analysis we also adjusted the curves for the presence of competing risks with the Fine and Gray analysis.
  
  
  RESULTS
  After the matching procedure, 2,890 patients were included in the analysis (1,445 in each group). Baseline characteristics were similar for all covariates including: age, diabetes, BMI, Center-experience, coronary artery disease, cancer, literacy, hypertension, race, previous HD, gender, pre-dialysis care, family income, peripheral artery disease and year of starting PD. Mortality rate was higher in CAPD patients (SHR1.44 CI95%1.21-1.71) compared to APD, but no difference was observed for technique failure (SHR0.83 CI95%0.69-1.02) nor for time till the first peritonitis episode (SHR0.96 CI95%0.93-1.11).
  
  
  CONCLUSIONS
  In the first large PD cohort study with groups balanced for several covariates using propensity score matching, PD modality was not associated with differences in neither time to first peritonitis nor in technique failure. Nevertheless, patient survival was significantly better in APD patients.
authors.affiliation: School of Medicine, UNESP, Botucatu, Brazil.
authors.forename: Gabriela de Carvalho
authors.initials: Gde C
authors.lastname: Beduschi
authors.affiliation: Graduate Program in Medicine and Health Sciences, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil.
authors.forename: Ana Elizabeth
authors.initials: AE
authors.lastname: Figueiredo
authors.affiliation: School of Medicine, UNESP, Botucatu, Brazil.
authors.forename: Marcia
authors.initials: M
authors.lastname: Olandoski
authors.affiliation: School of Medicine, UNESP, Botucatu, Brazil.
authors.forename: Roberto
authors.initials: R
authors.lastname: Pecoits-Filho
authors.affiliation: School of Medicine, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Brazil.
authors.forename: Pasqual
authors.initials: P
authors.lastname: Barretti
authors.affiliation: School of Medicine, UNESP, Botucatu, Brazil.
authors.forename: Thyago Proenca
authors.initials: TP
authors.lastname: de Moraes
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010531:Peritoneal Dialysis, Continuous Ambulatory / Q000379:methods* / Q000401:mortality*; D057216:Propensity Score; D011446:Prospective Studies; D012307:Risk Factors; D015996:Survival Rate