What's wrong with missing dialysis? Pattern and outcomes of dialysis attendance in the Northern Territory, 1995-2011

Aim: To describe the pattern and outcomes of variation of haemodialysis attendance in the Northern Territory (NT).

Background: No Australian reports and only few dated reports elsewhere have described rates and outcomes of haemodialysis attendance, which may impact on outcomes.

Methods: All patients starting haemodialysis in the NT between 1st January 1995 and 31st December 2011 were included by linking NT public hospitalisation, subsidised patient travel and ANZDATA registry data. Mean yearly attendance from haemodialysis start was calculated, and associations examined by multiple linear regression. Fine and Gray competing risks proportional hazards models (CR-PH) were used to examine the chances of death and transplantation per year by mean yearly attendance category, adjusted for demographic and clinical differences; negative binomial regression (NBR) was used to model adjusted incidence rate ratios (IRR) for hospitalisation.

Results: Of 618 patients registered for haemodialysis for ≥1 year, 49.5% attended 2.0–2.75 haemodialysis sessions/week on average in the first year; 29.3% attended <2.0. Indigenous status was associated with lower mean attendance; relocation from remote areas was not. Lower mean attendance was associated with higher rates of death in adjusted CR–PH models: <2.0 sessions/week (compared with >2.75) sub-hazard ratio (SHR, with 95% CI) 3.47 (1.50–8.07), 2.0–2.75 sessions/ week SHR 1.73 (0.75–3.96). No patients attending <2.0 sessions/week were transplanted, and few attending 2.0–2.75 (SHR 0.37 (0.07–1.91)). An adjusted NBR model showed higher rates of hospitalisation:<2.0 sessions/week IRR 2.95 (2.34–3.72), 2.0–2.75 sessions/week IRR 2.03 (1.67–2.47).

Conclusions: Attending <2.75 sessions/week on average was associated with poorer outcomes, with particular risks for <2.0 sessions/week. Relocation for treatment did not necessarily result in lower haemodialysis attendance in the first year. Understanding reasons for missing dialysis is needed to improve outcomes.