Survival of elderly dialysis patients is predicted by both patient and practice characteristics

Background: Increasing numbers of elderly patients facedecisions about the management of end-stage kidney disease. Improvedunderstanding of contemporary patient and practice factors influencingprognosis may assist decision making for individual patients and their careproviders.

Methods: This is a prospective registry study using multivariable proportionalhazards models.

Atotal of 1781 patients aged ≥75 years at dialysis initiation recorded inANZDATA, the Australia and New Zealand renal replacement registry, betweenJanuary 2002 and December 2005.

Thepatient characteristics were demographic and comorbid conditions. The practicecharacteristics were late referral, access at dialysis initiation and intendeddialysis modality (modality established by 90 days).

Thestudy outcome was mortality censored at 31 December 2007 or at recovery of renalfunction (of at least 30 days), transplantation or loss to follow-up.

Results: Median follow-up was 2.3 years (interquartile range 1.1–3.3 years)during which time, 65% of the patients died. Baseline factors independentlyassociated with mortality were older age [hazard ratio (HR) 1.24 for 5-yearincrease, 95% confidence interval (CI) 1.13–1.36], body mass index <18.5 (HR1.78, 95% CI 1.33–2.38), number of comorbidities (one comorbidity HR 1.38, 95%CI 1.13–1.69; two comorbidities HR 1.55, 95% CI 1.27–1.89; three or morecomorbidities HR 1.89, 95% CI 1.55–2.31), late referral (HR 1.19, 95% CI1.02–1.39), peritoneal dialysis as intended modality (HR 1.26, 95% CI1.08–1.47) and unprepared access (HR 1.43, 95% CI 1.23–1.67).

Thelimitations of the study were the observational nature of the analysis,potential selection bias introduced through analysis of a group who actuallycommenced dialysis and the potential confounding from unmeasured factors ordichotomous reporting of comorbidities.

Conclusions: Within the elderly cohort, other patientcharacteristics have a greater association with mortality than 5-year ageincrements. Even after consideration of patient characteristics, practicefactors have a striking impact on the survival of elderly patients commencingdialysis. In the absence of randomized studies, efforts to enhance theidentification and preparation of elderly patients for dialysis may improveoutcomes within current settings.