Risk factors for suboptimal dialysis initiation: a prospective cohort study

Background — Suboptimal dialysis initiation is common and is associated with increased morbidity and mortality. We sought to determine risk factors for suboptimal dialysis among patients with advanced CKD.

Methods — Prospective cohort study that enrolled English speaking patients without cognitive impairment followed in multidisciplinary kidney clinics across four regional kidney programs in Ontario, Canada. Patients completed a 6-month follow-up visit with further follow-up using healthcare administrative data. The primary outcome was suboptimal dialysis initiation defined by dialysis initiation during a hospitalization or with a central venous catheter in patients <75 years old. Adjusted cause specific hazard models were used to examine the association of pre-specified characteristics with suboptimal dialysis.

Results — 366 patients were included, 122 (33%) patients had a suboptimal dialysis start (69% of dialysis starts) over a median follow up of 1.9 (IQR 0.7-2.5) years. Higher hemoglobin (time-varying) was associated with a lower risk of suboptimal dialysis initiation (adjusted hazard ratio (aHR) 0.96, 95% CI 0.95-0.98). The mean (SD) hemoglobin in those with suboptimal dialysis initiation was 10.7 (1.5) g/dL. Higher comorbidity index and greater number of nephrologist visits within the past 6 months were associated with a higher risk of suboptimal dialysis initiation (aHR 1.17, 95% CI 1.01-1.35 and 1.70, 95% CI 1.39-2.08, respectively). Measures of health literacy, kidney disease knowledge and influenza vaccination were not associated with suboptimal dialysis initiation. A secondary analysis defining suboptimal dialysis initiation by dialysis initiation during a hospitalization showed similar results.

Conclusions — Suboptimal dialysis initiation was common despite established nephrology follow-up. Our study did not find readily modifiable patient-related risk factors for suboptimal dialysis initiation.