Center Effects and Peritoneal Dialysis Peritonitis Outcomes: Analysis of a National Registry.

BACKGROUND

Peritonitis is a common cause of technique failure in peritoneal dialysis (PD). Dialysis center-level characteristics may influence PD peritonitis outcomes independent of patient-level characteristics.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS: Using Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) data, all incident Australian PD patients who had peritonitis from 2004 through 2014 were included.

PREDICTORS

Patient- (including demographic data, causal organisms, and comorbid conditions) and center- (including center size, proportion of patients treated with PD, and summary measures related to type, cause, and outcome of peritonitis episodes) level predictors.

OUTCOMES & MEASUREMENT: The primary outcome was cure of peritonitis with antibiotics. Secondary outcomes were peritonitis-related catheter removal, hemodialysis therapy transfer, peritonitis relapse/recurrence, hospitalization, and mortality. Outcomes were analyzed using multilevel mixed logistic regression.

RESULTS

The study included 9,100 episodes of peritonitis among 4,428 patients across 51 centers. Cure with antibiotics was achieved in 6,285 (69%) peritonitis episodes and varied between 38% and 86% across centers. Centers with higher proportions of dialysis patients treated with PD (>29%) had significantly higher odds of peritonitis cure (adjusted OR, 1.21; 95% CI, 1.04-1.40) and lower odds of catheter removal (OR, 0.78; 95% CI, 0.62-0.97), hemodialysis therapy transfer (OR, 0.78; 95% CI, 0.62-0.97), and peritonitis relapse/recurrence (OR, 0.68; 95% CI, 0.48-0.98). Centers with higher proportions of peritonitis episodes receiving empirical antibiotics covering both Gram-positive and Gram-negative organisms had higher odds of cure with antibiotics (OR, 1.22; 95% CI, 1.06-1.42). Patient-level characteristics associated with higher odds of cure were younger age and less virulent causative organisms (coagulase-negative staphylococci, streptococci, and culture negative). The variation in odds of cure across centers was 9% higher after adjustment for patient-level characteristics, but 66% lower after adjustment for center-level characteristics.

LIMITATIONS

Retrospective study design using registry data.

CONCLUSIONS

These results suggest that center effects contribute substantially to the appreciable variation in PD peritonitis outcomes that exist across PD centers within Australia.