Abstract
Background: Peritonitis is the main cause of morbidity and dropout from peritoneal dialysis (PD)
program.
Objectives: We aimed to determine risk factors predisposing to PD-associated peritonitis.
Patients and Methods: As a retrospective cohort research, on 235 PD individuals with 4277 patientmonths of follow up, 170 episodes of peritonitis was reported in 93 patients. Data were extracted
from medical records using a template. Standard as well as zero-inflated negative binominal
regression was used to model the association between patients’ characteristics and the peritonitis
rate. Cox-proportional hazard (PH) adjusted model was used to determine the effect of factors on
the peritonitis-free survival.
Results: With a mean (SD) body mass index (BMI) of 18.7(3.4) kg/m2, 109 (46.4%) of them were
male. With a median (95% CI) follow-up time of 19 (16 to 36) months, the rate of peritonitis was
0.48 episode per patient-year. The most common micro-organism detected was coagulase-negative
staphylococci (n=54; 31.7%). The only variable which was associated with a higher rate of peritonitis
was BMI (rate ratio [RR]: 1.07; 95% CI 1.01 to 1.14; P value=0.031). Comparing to patients with
lower education, patients with higher than elementary school of education had higher peritonitisfree survival (with hazard ratio [HR]=0.51; 95%CI 0.33-0.79, P value=0.003) and higher chance of
having no peritonitis [odds ratio (OR):1.97; 95% CI 1.08 to 3.59; P value=0.029].
Conclusions: Peritonitis is still a major concern in PD patients. BMI was a risk factor for higher
peritonitis rate. Higher education level was associated with lower peritonitis-free survival and higher
chance of having no peritonitis.