Associations of Dialysis Modality and Infectious Mortality in Incident Dialysis Patients in Australia and New Zealand

Johnson, David W.; Dent, Hannah; Hawley, Carmel M.; McDonald, Stephen P.; Rosman, Johan B.; Brown, Fiona G.; Bannister, Kym M.; Wiggins, Kathryn J.

doi:10.1053/j.ajkd.2008.06.032

« Previous Next »American Journal of Kidney Diseases
Volume 53, Issue 2 , Pages 290-297, February 2009

Associations of Dialysis Modality and Infectious Mortality in Incident Dialysis Patients in Australia and New Zealand

David W. Johnson, PhD
- Australia and New Zealand Dialysis and Transplant Registry, Adelaide, Australia
- Department of Renal Medicine, University of Queensland at Princess Alexandra Hospital, Brisbane, Australia
- Address correspondence to David W. Johnson, PhD, Department of Nephrology, Level 2, ARTS Bldg, Princess Alexandra Hospital, Ipswich Rd, Woolloongabba, Brisbane Qld 4102, Australia
Hannah Dent, BSc(Hons)
- Australia and New Zealand Dialysis and Transplant Registry, Adelaide, Australia
- Discipline of Public Health, University of Adelaide, Adelaide, Australia
Carmel M. Hawley, MMedSci
- Australia and New Zealand Dialysis and Transplant Registry, Adelaide, Australia
- Department of Renal Medicine, University of Queensland at Princess Alexandra Hospital, Brisbane, Australia
Stephen P. McDonald, PhD
- Australia and New Zealand Dialysis and Transplant Registry, Adelaide, Australia
- Department of Nephrology and Transplantation Services, University of Adelaide at the Queen Elizabeth Hospital, Adelaide, Australia
Johan B. Rosman, MD
- Australia and New Zealand Dialysis and Transplant Registry, Adelaide, Australia
- Renal Department, Middlemore Hospital, Otahuhu, Auckland, New Zealand
Fiona G. Brown, PhD
- Australia and New Zealand Dialysis and Transplant Registry, Adelaide, Australia
- Department of Nephrology, Monash Medical Center, Clayton, Victoria, Australia
Kym M. Bannister, MD
- Australia and New Zealand Dialysis and Transplant Registry, Adelaide, Australia
- Department of Nephrology, Royal Adelaide Hospital, Adelaide, Australia
Kathryn J. Wiggins, MD
- Australia and New Zealand Dialysis and Transplant Registry, Adelaide, Australia
- University of Melbourne Department of Nephrology, St Vincent's Hospital, Fitzroy, Victoria, Australia

Received 25 February 2008; accepted 7 July 2008. published online 22 September 2008.

Background

The aim of the present investigation is to compare rates, types, causes, and timing of infectious death in incident peritoneal dialysis (PD) and hemodialysis (HD) patients in Australia and New Zealand.

Study Design

Observational cohort study using the Australian and New Zealand Dialysis and Transplant Registry data.

Setting & Participants

The study included all patients starting dialysis therapy between April 1, 1995, and December 31, 2005.

Predictor

Dialysis modality.

Outcomes & Measurements

Rates of and time to infectious death were compared by using Poisson regression, Kaplan-Meier, and competing risks multivariate Cox proportional hazards model analyses.

Results

21,935 patients started dialysis therapy (first treatment PD, n = 6,020; HD, n = 15,915) during the study period, and 1,163 patients (5.1%) died of infectious causes (PD, 529 patients; 7.6% versus HD, 634 patients; 4.2%). Incidence rates of infectious mortality in PD and HD patients were 2.8 and 1.7/100 patient-years, respectively (incidence rate ratio PD versus HD, 1.66; 95% confidence interval [CI], 1.47 to 1.86). After performing competing risks multivariate Cox analyses allowing for an interaction between time on study and modality because of identified nonproportionality of hazards, PD consistently was associated with increased hazard of death from infection compared with HD after 6 months of treatment (<6 months hazard ratio [HR], 1.08; 95% CI, 0.76 to 1.54; 6 months to 2 years HR, 1.31; 95% CI, 1.09 to 1.59; 2 to 6 years HR, 1.51; 95% CI, 1.26 to 1.80; >6 years HR, 2.76; 95% CI, 1.76 to 4.33). This increased risk of infectious death in PD patients was largely accounted for by an increased risk of death caused by bacterial or fungal peritonitis.

Limitations

Patients were not randomly assigned to their initial dialysis modality. Residual confounding and coding bias could not be excluded.

Conclusions

Dialysis modality selection significantly influences risks, types, causes, and timing of fatal infections experienced by patients with end-stage kidney disease in Australia and New Zealand.

Index Words: Bacteremia, continuous ambulatory peritoneal dialysis, hemodialysis, peritoneal dialysis, peritonitis, pneumonia, septicemia, bacterial infection, fungal infection, incidence, prevalence, treatment modality, viral infection